ACE Management Agent launcher

@see ACE-347

Usage:

usage: java -jar org.apache.ace.agent.launcher [options] [configurationfile]
 -h,--help      print this message
 -v,--verbose   verbose logging


Notes:

* Simplified config code (using commons-cli).
* Includes good default configuration
 
 TODOs:

* Support simple single agent through CLI options
* Remove 'default' agent from default configuration?
* Extend configuration documentation
* Clean felix-cache dir on restart?