add support for fancier /repos/:repo_key/commits/ API (#40)
enhancements to /repos/ API (#47)

also add test of repo info endpoint's default description detection
added /repos/{repos_key}/branches (#48)
basic comment based organization to start with (#54)
added /repos/{repo_key}/branches/{branch_name} (#53)
Move get_repos_commit to correct comment-org section (#54)
porcelain methods on github seem to support branch_or_tag_or_commit always, but precedence maybe shouldn't be the same
correct precedence for sha vs tags/branches
added github equivalent  /repos/:repo_key/tags API (#50)
fix minor issue introduced by d99d9c2
added non-github api for retrieving tag by name /repos/{repo_key}/tags/{tag_name} (#59)
add support for retrieving .diff (#56)
be consistent with API urls rather than random github endpoint (also like /compare/ when we implement it)
make pep8 happy
add reference output: wget'd https://github.com/hulu/restfulgit/commit/d408fc2428bc6444cabd7f7b46edbe70b6992b16.diff
add test for /commits/SHA.diff endpoint
add test for /repos/:repo_key/tags
add test for /repos/:repo_key/branches
corrections to _convert_branch() to match GitHub's format
add stub /repos/:repo_key/contents/:path impl