Import which.py to make things more helpful off a local clone
Add a shebang on sccache.py
Add a basic README.md
Add a note about the lack of local storage cleanup
Bug 1007942 - Remove SCCACHE_NO_HTTPS, and rely on "normal" boto config instead. r=mshal
Bug 1011445 - Add cache control metadata. r=mshal
Bug 1006578 - more helpful error when server.py fails; r=glandium