Read `xcdatamodeld` current_version from plist named `.xccurrentversion` if found.
Fixed obvious logic error.
Assign current_version with terser syntax.
Updated documentation comments
get file reference instead of file path for current version from plist.
Added spec to cover 'handles xccurrentversion file'
stub .xccurrentversion file in group_spec
Added rake task to run given spec file
Added CoreData model spec fixture
Added CoreData model spec using fixtures
Merge branch 'master' of https://github.com/Ashton-W/Xcodeproj

Conflicts:
	spec/project/object/group_spec.rb
Fixed xcdatamodeld current_version not being set correctly
Updated spec.
Merge commit '96da037af547efcef14d3f65f23cc41939143f63'
[Project] Minor clean-up
[Project] Add path attribute, add Project.open, and refactor initialization
[Project] Rename #save_as to #save
[PBXFileReference] Minor clean up
[PBXGroup, PBXFileReference] Added `#real_path` and `#parent`
[Cleanup]
[Group] Deprecate parameter to specify a subgroup of `#new_file`, `#group`, and related
[Cleanup]
[PBXGroup] removed `#new_xcdatamodel_group`