SEC-1953: Spring Security Java Config support

This is the initial migration of Spring Security Java Config from the
external project at
https://github.com/SpringSource/spring-security-javaconfig
SEC-1953: Polish bundlor warnings
SEC-1953: Polish
#138 Tests for WebSecurityExpressionHandler bean existing
#138 WebInvocationPrivilegeEvaluator has default value
#137 WebSecurityConfigurerAdapter no longer uses getClass() for logger

Previously it was difficult to change log levels due to CGLIB proxying of
the class which impacted the logger name.
remove snapshot repo references
[artifactory-release] Release version 3.2.0.M2
Next development version
SEC-2192: Create DEFAULT_FILTER_NAME
Merge in AbstractSecurityWebApplicationInitializerTests.groovy
SEC-2187: Encode query parameter names and values in return_to URL
SEC-2187: Polish

Create private utf8UrlEncode method to improve readability
SEC-2191: Remove AuthenticationManagerBuilder default constructor

This ensures that users must choose what ObjectPostProcessor is being used
with AuthenticationManagerBuilder. To make things easier for users, we now
automatically add an AuthenticationManagerBuilder object that can be used
for creating an AuthenticationManager with @Autowired.
SEC-2207: Update Gradle to 1.6
SEC-2195: Update Groovy, Geb, Spock, httpcomponents, and Jetty
SEC-2207: AspectJPlugin uses compileAspect and compileTestAspect
SEC-2217: Sonar Runner
SEC-2206: Gradle Propdeps
SEC-2209: add pom.xml