Use SemVer build version for ChefDK projects

This format produced a fully SemVer-compliant build version like:

MAJOR.MINOR.PATCH-PRERELEASE+TIMESTAMP.git.COMMITS_SINCE.GIT_SHA

The timestamp can optionally be omitted by passing the `--no-timestamp` 
to the `omnibus` CLI.

I ran a full-matrix test of this through CI also:
http://manhattan.ci.opscode.us/view/CHEFDK%3A%20Omnibus%20Build%20Pipeline/job/chefdk-trigger-ad_hoc/3/downstreambuildview/

/cc @opscode/release-engineers @opscode/client-eng