No longer run in verbose mode by default

Closes #211
Enable -Wmismatched-tags
These scripts have moved to the pyston_perf repo
Try to not repeatedly scan through the 'free' bitfield

Seems to help by a couple percent.
Can optimize the initial branch away since we know we'll always execute the loop at least once
Minor optimizations
Decrease the collection frequency
Was spuriously failing rewrites by not marking them as succeeded
Pypa vs Python parser tests

Signed-off-by: Vinzenz Feenstra <evilissimo@gmail.com>