Bug 1390968: python-3 compatibility for python/**/*.py; r=Alex_Gaynor,gps

This passes `python3 -mcompileall`.  Changes:

 * use `0o` prefix for octal literals
 * print as a function
 * except .. as
 * use six.reraise to replace a multi-argument raise statement
 * use six.string_types and six.moves.configparser
 * remove uses of `L` suffix for long integers

MozReview-Commit-ID: KLaYRNHGpay

python/mach/setup.py

@@ -32,6 +32,7 @@ setup(
         'blessings',
         'mozfile',
         'mozprocess',
+        'six',
     ],
     tests_require=['mock'],
 )