* diff-cover now calls git diff multiple times to collect
unstaged, staged, and committed changes.

* Removed the --git-branch command line argument
Updated README to match current implementation
Enforced alphabetical ordering of source names.
Added tests for overlapping hunks.
Git diff reporter now combines overlapping hunks from
staged/unstaged/committed changes.
Pep8/Pylint fixes
Merge pull request #5 from edx/will/uncommitted-changes

Will/uncommitted changes