[PATCH] Disable drpms for local repositories. BZ 1007097

[Zdenek Pavlas]

>  Why have the default be local=True?

To handle mixed cases.. I consider repo local iff 
*all* (not just the first or some of) URLs are file://.
The len(self._urls)==0 case is handled in .check()

Now that I think of it more, maybe we should not add .local
at all, just use a simple "if repo.urls[0].startswith('file:')"
test in drpm.py..

> Also this assumes that most/all file:// repos. are on local disks, and
> not NFS mounted shares or similar things. It might be worth defaulting
> to no drpms, and documenting that people using slower NFS shares should
> change something to turn them back on ... but this just disables them.

While slower than local disk, typical NFS is still way faster than
drpm rebuild speed.

>  Maybe have the logic be "if the user hasn't configured
> deltarpm_percentage

Yes, per-repo option should be used first. Is there a better check 
than the obvious "ayum.conf.option != repo.option" to tell it was
overriden?