Cleanup and standardize omnibus-software definitions

This is a general cleanup of all the cruft we have accumulated over the years in omnibus-software. This commit will put omnibus-software@master in parity with omnibus@master. The 3.2-stable branch should not receive these backports.

- [x] Cleanup copyright headers for consistency
- [x] Use `with_standard_compiler_flags` and `with_embedded_path` everywhere
- [x] Refactor crazy hacks 
- [x] Fix deprecations
- [X] Add basic CI coverage testing
- [X] Get [passing builds of Enterprise Chef](http://wilson.ci.opscode.us/job/private-chef-build/308/)
- [X] Get [passing builds of Chef](http://ci.opscode.us/job/chef-client-build/1680/)
- [X] Get passing builds of ChefDK

:warning: I worked on this all day (Saturday), but I still need to run full builds of all pipelines through. I'll do that on Sunday.

/cc @lamont-granquist @opscode/release-engineers