chefdk work

- software + project dfns for chefdk
- pulls in new omnibus and omnibus-software
- package-scripts for chefdk
- fixes to allow jenkins to build chefdk via OMNIBUS_PROJECT_NAME
Update omnibus to build .pkg files on OS X
fix cherry-pick merge
remove unnecessary commented out overrides
Merge pull request #120 from opscode/lcg/include-berkshelf

add chefdk project and install scripts