PluginDownloader: If bot is running on Python 3, run 2to3 on installed plugins if they are detected as being designed for Python 2.
ChannelStats & Conditionnal & Format & Karma & Limiter & MessageParser & Misc & Network & PluginDownloader & Seen & ShrinkUrl & Status & String & Time & Topic & User & Web: Update messages.pot.
Socket: Check if certertificate file exists before using it.
Merge branch 'testing' of git://github.com/ProgVal/Limnoria into testing