XD-1510: Lower some logging levels

The initial amount of logging for xd-singlenode (worst case) was 148 lines (790 when `fold`ed).

See below for the result with this PR applied on admin/container.
* Note that lines with LoggingApplicationListener should be fixed by https://github.com/spring-projects/spring-boot/pull/1255
* Not sure about how to address the ConfigurationClassEnhancer lines
* Some of the remaining logging seems to be java.util.Logging by tomcat
* Some of the client ZK stuff, even though it is using slf4j, seems to happen before our conf is applied

With this PR applied, we get the following for admin:
```

 _____                           __   _______
/  ___|          (-)             \ \ / /  _  \
\ `--. _ __  _ __ _ _ __   __ _   \ V /| | | |
 `--. \ '_ \| '__| | '_ \ / _` |  / ^ \| | | |
/\__/ / |_) | |  | | | | | (_| | / / \ \ |/ /
\____/| .__/|_|  |_|_| |_|\__, | \/   \/___/
      | |                  __/ |
      |_|                 |___/
1.0.0.BUILD-SNAPSHOT             eXtreme Data


Started : AdminServerApplication
Documentation: https://github.com/spring-projects/spring-xd/wiki

16:09:09,038  WARN main logging.LoggingApplicationListener - Logging environment value 'file:/Users/ebottard/Documents/projects/spring-xd/build/dist/spring-xd/xd/config///xd-admin-logger.properties' cannot be opened and will be ignored
16:09:10,812  WARN main annotation.ConfigurationClassEnhancer - @Bean method ScopeConfiguration.stepScope is non-static and returns an object assignable to Spring's BeanFactoryPostProcessor interface. This will result in a failure to process annotations such as @Autowired, @Resource and @PostConstruct within the method's declaring @Configuration class. Add the 'static' modifier to this method to avoid these container lifecycle issues; see @Bean Javadoc for complete details
16:09:10,823  WARN main annotation.ConfigurationClassEnhancer - @Bean method ScopeConfiguration.jobScope is non-static and returns an object assignable to Spring's BeanFactoryPostProcessor interface. This will result in a failure to process annotations such as @Autowired, @Resource and @PostConstruct within the method's declaring @Configuration class. Add the 'static' modifier to this method to avoid these container lifecycle issues; see @Bean Javadoc for complete details
16:09:13,897  WARN main logging.LoggingApplicationListener - Logging environment value 'file:/Users/ebottard/Documents/projects/spring-xd/build/dist/spring-xd/xd/config///xd-admin-logger.properties' cannot be opened and will be ignored
16:09:14,776  WARN main logging.LoggingApplicationListener - Logging environment value 'file:/Users/ebottard/Documents/projects/spring-xd/build/dist/spring-xd/xd/config///xd-admin-logger.properties' cannot be opened and will be ignored
juil. 15, 2014 4:09:16 PM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Tomcat
juil. 15, 2014 4:09:16 PM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.54
juil. 15, 2014 4:09:17 PM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring embedded WebApplicationContext
juil. 15, 2014 4:09:18 PM org.apache.catalina.core.ApplicationContext log
INFO: jolokia: No access restrictor found at classpath:/jolokia-access.xml, access to all MBeans is allowed
16:09:18,789  INFO main util.XdConfigLoggingInitializer - XD Home: /Users/ebottard/Documents/projects/spring-xd/build/dist/spring-xd/xd
16:09:18,790  INFO main util.XdConfigLoggingInitializer - Transport: redis
16:09:18,790  INFO main util.XdConfigLoggingInitializer - Zookeeper at: localhost:2181
16:09:18,791  INFO main util.XdConfigLoggingInitializer - Analytics: redis
juil. 15, 2014 4:09:18 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-nio-9393"]
juil. 15, 2014 4:09:18 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-9393"]
juil. 15, 2014 4:09:18 PM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
INFO: Using a shared selector for servlet write/read
``` 

container:
```

 _____                           __   _______
/  ___|          (-)             \ \ / /  _  \
\ `--. _ __  _ __ _ _ __   __ _   \ V /| | | |
 `--. \ '_ \| '__| | '_ \ / _` |  / ^ \| | | |
/\__/ / |_) | |  | | | | | (_| | / / \ \ |/ /
\____/| .__/|_|  |_|_| |_|\__, | \/   \/___/
      | |                  __/ |
      |_|                 |___/
1.0.0.BUILD-SNAPSHOT             eXtreme Data


Started : ContainerServerApplication
Documentation: https://github.com/spring-projects/spring-xd/wiki

16:10:04,533  WARN main logging.LoggingApplicationListener - Logging environment value 'file:/Users/ebottard/Documents/projects/spring-xd/build/dist/spring-xd/xd/config///xd-container-logger.properties' cannot be opened and will be ignored
16:10:05,361  WARN main logging.LoggingApplicationListener - Logging environment value 'file:/Users/ebottard/Documents/projects/spring-xd/build/dist/spring-xd/xd/config///xd-container-logger.properties' cannot be opened and will be ignored
16:10:06,655  WARN main annotation.ConfigurationClassEnhancer - @Bean method ScopeConfiguration.stepScope is non-static and returns an object assignable to Spring's BeanFactoryPostProcessor interface. This will result in a failure to process annotations such as @Autowired, @Resource and @PostConstruct within the method's declaring @Configuration class. Add the 'static' modifier to this method to avoid these container lifecycle issues; see @Bean Javadoc for complete details
16:10:06,663  WARN main annotation.ConfigurationClassEnhancer - @Bean method ScopeConfiguration.jobScope is non-static and returns an object assignable to Spring's BeanFactoryPostProcessor interface. This will result in a failure to process annotations such as @Autowired, @Resource and @PostConstruct within the method's declaring @Configuration class. Add the 'static' modifier to this method to avoid these container lifecycle issues; see @Bean Javadoc for complete details
16:10:09,275  WARN main logging.LoggingApplicationListener - Logging environment value 'file:/Users/ebottard/Documents/projects/spring-xd/build/dist/spring-xd/xd/config///xd-container-logger.properties' cannot be opened and will be ignored
[2014-07-15 16:10:09.917] boot - 48145  INFO [main-SendThread(localhost:2181)] --- ClientCnxn: Socket connection established to localhost/127.0.0.1:2181, initiating session
[2014-07-15 16:10:09.936] boot - 48145  INFO [main-SendThread(localhost:2181)] --- ClientCnxn: Session establishment complete on server localhost/127.0.0.1:2181, sessionid = 0x1473a566dfc0003, negotiated timeout = 40000
[2014-07-15 16:10:09.940] boot - 48145  INFO [main-EventThread] --- ConnectionStateManager: State change: CONNECTED
16:10:10,026  WARN main logging.LoggingApplicationListener - Logging environment value 'file:/Users/ebottard/Documents/projects/spring-xd/build/dist/spring-xd/xd/config///xd-container-logger.properties' cannot be opened and will be ignored
16:10:11,165  WARN main logging.LoggingApplicationListener - Logging environment value 'file:/Users/ebottard/Documents/projects/spring-xd/build/dist/spring-xd/xd/config///xd-container-logger.properties' cannot be opened and will be ignored
juil. 15, 2014 4:10:12 PM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Tomcat
juil. 15, 2014 4:10:12 PM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.54
juil. 15, 2014 4:10:12 PM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring embedded WebApplicationContext
juil. 15, 2014 4:10:13 PM org.apache.catalina.core.ApplicationContext log
INFO: jolokia: No access restrictor found at classpath:/jolokia-access.xml, access to all MBeans is allowed
16:10:13,525  INFO main util.XdConfigLoggingInitializer - XD Home: /Users/ebottard/Documents/projects/spring-xd/build/dist/spring-xd/xd
16:10:13,526  INFO main util.XdConfigLoggingInitializer - Transport: redis
16:10:13,526  INFO main util.XdConfigLoggingInitializer - Hadoop Distro: hadoop22
16:10:13,528  INFO main util.XdConfigLoggingInitializer - Hadoop version detected from classpath: 2.2.0
16:10:13,528  INFO main util.XdConfigLoggingInitializer - Zookeeper at: localhost:2181
16:10:13,529  INFO main util.XdConfigLoggingInitializer - Analytics: redis
juil. 15, 2014 4:10:13 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-nio-auto-1"]
juil. 15, 2014 4:10:13 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-auto-1"]
juil. 15, 2014 4:10:13 PM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
INFO: Using a shared selector for servlet write/read
```
OK, let's aim for that.
Related question: when running singlenode, should we try to contextualize what pertains to admin, and what to container (with NDC maybe?)