profile: Support yappi builtins option

yappi support profiling also builtin python functions. This patch adds a
new configuration value to enable profiling builtins in an application
wide profile, and a new builtins kwarg to the profile decorator.

This option can be handy when trying to understand why code is
expensive.

Change-Id: I67c6fc52ac64f8ff7f13471a53129a66361192ca
Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/27787
Reviewed-by: Francesco Romani <fromani@redhat.com>
Reviewed-by: Saggi Mizrahi <smizrahi@redhat.com>