Finish porting djblets to Python 2/3 compatibility.
Review Request #5307 — Created Jan. 24, 2014 and submitted
Finish porting djblets to Python 2/3 compatibility.
This change finishes up the last bits of djblets for Python 2/3 compatibility.
Most of this was just left-over pieces from my previous efforts, with a little
bit of newly-written code sprinkled in.
Ran unit tests.
