use `lstat()` instead of `stat()` to properly handle symbolic links
Add optional commit throttling
Make chunk size configurable
Clean up throttling and sha1 from feedback
Merge branch 'master' of github.com:ambv/bitrot

Conflicts:
	src/bitrot.py
Merge branch 'periodic-commits' of git://github.com/yang/bitrot into yang-periodic-commits

Conflicts:
	src/bitrot.py