Don't check exit codes when patching.

Similar to what we did in 427769c we need to ignore checking
exit codes for patch -N command so that they can be run multiple
times.

The motivation here is that I would like to use this to patch
virtual env's created by tox. Tox doesn't provide a good hook
to call post_process (which patches files) only once so the
idea here is we'll just let it call post_process all the time...

Change-Id: I866e7a3e1fd492d7d4c08eb55cde02f2dfa16c9a
Add 'is' operator to extra specs ops.

Boolean values for capabilities don't work because extra_specs are
all converted to unicode. The scheduler will then check, for example,
if the boolean 'True' is equal to the unicode string 'True', and will
always return False. This patch allows admins to specify '<is> True'
in extra_specs, which will compare successfully to boolean True.

Fixes bug: 1146306

Change-Id: Id0e6dcfb71eb0943a16bba551ec23c4d57206550
Merge "Add 'is' operator to extra specs ops."