updated changelog and version for alpha12
- renamed youtube to client
- seperated client and video functions
- added main in youtube package for fast local testings
code cleaning
- Accelerated resolving of video URLs (almost 2x as fast)
 added test for some low resolutions
- ADD: support for 3D videos (can be disabled via setting)
- ADD: Show 'Published on' and 'Channel' in the description of a video
(can be disabled via setting)
changed name of the addon
Merge pull request #1 from bromix/alpha12_dev

Alpha12 dev