server: use local fixed _bootstrap when appropriate

server: use local fixed _bootstrap when appropriate

When running on python versions 2.6.0 through 2.6.2, we use a local copy
of the python 2.6.6 _bootstrap method of Process, to ensure that we have
the fix for http://bugs.python.org/issue5313. This avoids the "hang" of
the bitbake process at 0% progress during the parsing on older distros
like Fedora 12.

Signed-off-by: Chris Larson <chris_larson@mentor.com>