srpm installs

I'm playing at getting src.rpm installs working with rpm-python.  I
can't promise anything particularly pretty or quick as I'm not a C
hacker, but I should be able to implement it simply as part of
addInstall or stand alone.

Would anyone be intrested when I have something workable/presentable
aned should I diff against HEAD (4.3 devel) or 4.2 branch

Paul