End the charade (farce?) that we are using upload.py unaltered.
Cut all the unused stuff.
Indent using tabs to match the rest of the file.

Next: rewrite MercurialVCS to use mercurial package,
to avoid overhead of forking off a new hg command
multiple times for every file.  And parallelize upload.

R=gri
CC=golang-dev
https://golang.org/cl/2009046