fix for issue #240 (srx-branch cluster fact gather)

fix for jnpr.junos.utils.config.Config.load() ... when:
   configuration results in an rpc-error that does not contain
   any error-severity='error'; rather contains 'warning'.
updates to fix facts
fix fact gather order
Merge remote-tracking branch 'juniper/master'
Merge pull request #250 from jeremyschulman/master

bug fixes relating to fact gather