Enabled test.
Migrated ProcessControllerTest to process-test API.
Adding HTTP DELETE support to ProxyServlet.
Adding HTTP PUT support to ProxyServlet.
[FABRIC-1052] Clean all resources which were locked during Fabric recreation
Adding support for HTTP OPTIONS method.

Motivation:
The proxy should be able to proxy OPTIONS request especially as this
might otherwise stop target services that use Cross Origin Resource
Sharing (CORS) from working.
To enable CORS we also had to remove the filtering of the 'ORIGIN'
request header and allow it to added to the proxied request.
#1102: Fixed container login on git http server, so it also works when starting fabric with bin/fabric8 that may cause JAAS to be not initialized asap, which would cause git http server to fail authentication and git sync not to work. Thanks to Ioannis good idea how to get this fixed.
Process test API now uses FabricConstants.
Initialized test ProcessManagerService.
AbstractProcessTest doesn't have to catch IllegalThreadStateException anymore!
Fixed Javadoc.
Improved jvm.config generation.
Refactoring.
[FABRIC-1051] invoke Git-GC after every 40th commit
first spike of #1475 so we can detect if a configuration changes (such as an environment variable or controller) so we know if we need to restart the child process
#1475 add detection in the install/update process if we actually insert, update or delete any files so we know when we need to restart a process; also keep track of the changes so we can log why we are restarting a process
avoid possible exception if there's no etc folder
#1475 fix bug on deploy/lib dir mix up and only cause a restart if we update a shared library
#1475 always run the install task on updates of process containers (whether the environment changes or not)