Refactoring the registry function out of the already too big CmdLineParser class
Added unit test (with some integrational parts)
deprecated the old methods
redirecting uses to new methods in registry
Merge branch 'optionhandlerregistry' of https://github.com/sfuhrm/args4j into optionhandlerregistry

Conflicts:
	args4j/src/org/kohsuke/args4j/CmdLineParser.java
Enhanced some Javadoc
Rely on static imports