Add 'skip' flag to skip plugin execution completely.
Add 'skipNoGit' flag to skip plugin execution if run from a non-git folder.
Merge branch 'master' of github.com:koraktor/mavanagaiata

Conflicts:
	src/main/java/com/github/koraktor/mavanagaiata/mojo/AbstractGitMojo.java
small changes to accommodate internal API changes. Turn version back to non-snapshot
Merge pull request #22 from hgschmie/master

Added `skip` and `skipNoGit` parameters