Implemented invalidation of files on CDN
Merge branch 'master' into invalidate-files

Conflicts:
	lib/asset_sync/config.rb
	spec/unit/storage_spec.rb
Default Config Values for cdn invalidation
Exclude region from fog options in cdn invalidate
Use / at start of filenames for invalidation
Use map instead of inject for invalidated files
Merge branch 'anark-invalidate-files'

Conflicts:
	spec/unit/asset_sync_spec.rb