#39 maven subprojects

[Leo Freitas]

Like parser and typechecker, the VCG should also be a sub-project-type in maven (i.e. vcg-z, vcg-zeves, vcg-circus, etc). At the moment, only Z VCs are created, but for Circus (and Circus time) there will be more, certainly. The same could be said for ZEVES (i.e. adding default grules, etc).