py3status v2.6

Ok I was a bit too hasty in my legacy module support code clean up and I broke quite a few things on the latest version 2.5 release sorry ! :(

highlights

• make use of pkgutil to detect properly installed modules even when they are zipped in egg files (manual install)
• add back legacy modules output support (tuple of position / response)
• new uname module inspired from issue 117 thanks to @ndalliard
• remove dead code

thanks !

• @coelebs on IRC for reporting, testing and the good spirit :)
• @ndalliard on github for the issue, debug and for inspiring the uname module
• @Horgix for responding to issues faster than me !