setup.py: drop compatibility with Python 2.4 and 2.5 (BC) The last blocker for dropping Python 2.4 was Centos 5. We now provide our own Mercurial package for Centos 5 with a bundled Python2.7. I'm therefore happy to officially drop compatibility with Python 2.4 (and Python 2.5 that nobody really cares about). This open the season for code cleanup. It is war's prize to take all vantage.