Merge pull request #189 from MosesMendoza/RE-246/master/make_build_extras_optional

(RE-246) Make build extras optional
Initial work on reorg into classes
Bring in changes to tar and util
Move under packaging
Correct load path modification in packaging.rb
Add version utils
Continue with params
Initial attempt at setting a PROJECT_ROOT
Config is a class, and Params is its own module
Initial support for loading from build defaults

Rename various methods for sanity
Try to break down into smaller methods, for readability
Define default configs in config.rb, because its better than other places
Enable loading defaults from default configs, so we have a way to get data
Add support for loading from envvars