yum-presto to get multicore support

[Andre Robatino]

For some people with fast connections/slow PCs, using deltarpms via yum-presto
can be slower than downloading the full RPMs. Jonathan Dieter just did a Rawhide
build (yum-presto-0.8.0-1.fc18) that adds multicore support to yum-presto. Would
be interested if people would note what rebuild speed they get before and after
updating to this version, and if the speedup is close to linear. My experience
is that rebuilding drpms is CPU-bound so there's a good chance it will be.

I'd also be interested if someone more familiar with the deltaiso code than me
could venture an opinion as to whether the same basic approach would work for
that.

This is important because in recent years, networks have gotten faster but
individual CPUs mostly haven't. This will help deltarpms to keep up.

yum-presto build: http://koji.fedoraproject.org/koji/buildinfo?buildID=320054

RFE: Yum should use multiple threads to reassemble deltarpms
https://bugzilla.redhat.com/show_bug.cgi?id=701711