Add ANTLR Mavne plugin.
Add site descriptor.
Add base ANTL grammar.
Add specifiaction draft.
Add version option.
Ignore NetBeans config.
Add file extension for source code.
find all source files in current working directory.
Fix compile warning about unchecked conversion.
Add missing javadoc.
Make classes invisible.
Make it public for JCommander.
Process all found files.
Set debug level to trace.
Revert "Set debug level to trace."

This reverts commit c871ad109d619251abf6fb8e38e75294a41512fa.
Set debug level from env var.
First attempt of a grammar.