Add some upr mutation test cases
Make it a bit more interruptable
Fixed race condition

It could happen that `queue_operation()` was called before
`run()` was executed. Hence the `self.running` wasn't yet
set to true. With setting it to true right before starting
the thread this can't happen anymore.
Update pyupr to work corectly with latest stats changes

This change makes sure we call 'stats upr' instead of 'stats tap'
and also adds the 'eq_uprq:' prefix to all upr connection names.
using unittest2 for backward compatibility

tests failing in 2.6 because of check for mc backend
call to unittest.skip() being missing.  this method was
backported in unittest2.