Improve RPM Requires: filtering
Split EL and Fedora filtering. As Fedora has more perl modules available than EL, this allows to have more (all) features available in the Fedora builds. Tidy up EL7 filtering. Also, drop support for EL6, add a patch to fix a test suite failure (fixed in v2.0 branch already) and correct Version: to 2.0.1 as 2.0.2 has yet to be tagged.