This module, which catches segmentation faults and prints a backtrace
before exiting, was useful for a while, but I believe that it has now
outlived its purpose. It is altogether better to have a core dump from
which one can extract much more information than a usually-poor backtrace,
and core dumps are much better integrated into a typical Unix system.
In addition, the "fault" module was of course not all that portable.
The Xen DDK VM does not include Python, so it's best if we don't have to
require it for the build.
The built sources are still regenerated if necessary.
The PCRE_INFO_OKPARTIAL feature used by ovs-switchui was only introduced
in PCRE 7.2, so we need to check for that version or later, instead of
just for PCRE.
Thanks to Ian Campbell <Ian.Campbell@citrix.com> for reporting the problem.
