Fixing useSslClientAuthentication option:
- according documentation and internet examples to enable SSL client authentication on com.sun.net.httpserver.HttpsServer it is necessary to set params.setNeedClientAuth(useClientAuthentication) but also defaultSSLParameters.setNeedClientAuth(useClientAuthentication) in org.jolokia.jvmagent.JolokiaServer.JolokiaHttpsConfigurator#configure
- Boolean.getBoolean(auth) --> Returns true if and only if the system property named by the argument exists and is equal to the string "true".
  Boolean.valueOf(auth)    --> Returns a Boolean with a value represented by the specified string.
Enabling additional configuration parameters for HTTPS: secureSocketProtocol, keyStoreType, keyManagerAlgorithm, trustManagerAlgorithm

Default values:
secureSocketProtocol=TLS
keyStoreType=JKS
keyManagerAlgorithm=SunX509
trustManagerAlgorithm=SunX509
Enabling additional configuration parameters for "Attaching a Jolokia agent on the fly" related to  HTTPS: secureSocketProtocol, keyStoreType, keyManagerAlgorithm, trustManagerAlgorithm

Default values:
secureSocketProtocol=TLS
keyStoreType=JKS
keyManagerAlgorithm=SunX509
trustManagerAlgorithm=SunX509
Enabling additional configuration parameters for HTTPS: secureSocketProtocol, keyStoreType, keyManagerAlgorithm, trustManagerAlgorithm
- In JolokiaHttpsConfigurator#configure method SSLContext created in JolokiaServer#createHttpsServer should be use and not  SSLContext.getDefault()
Documentation update for:
- JVM Agent and SSL client authentication does not work #166
- Enabling additional configuration parameters for HTTPS #167
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/changes/changes.xml
Issue #169 Use system properties on the HttpClient that's used in J4pClientBuilder
* J4pClientBuilder.proxy
* J4pClientBuilder.useProxyFromEnvironment
Merge branch 'master' of https://github.com/nevenr/jolokia into 171-j4pclient-props
Tests for #169