[tvp] Telewizja Polska: new extractor for tvp.pl, fixes #1719

Thanks-To: mplonski

https://github.com/mplonski/linux/blob/master/tvp-dl.py
[common] Simplify og_search_property
FFmpegMetadataPP: don't enclose the values with " (fixes #1756)
[vine] Fix uploader extraction
Add support for d8.tv
Add extractor for gamekings.tv
[gamekings] Minor fixes (#1759)
Credit @jelly for gamekings extractor (#1759)
[tvp] Minor improvements (#1730)
Credit @saper for tvp IE (#1730)
release 2013.11.13
[youtube:playlist] Don't use the gdata api (closes #1508)

Parse the playlist pages instead
[youtube:playlist] Login into youtube if requested (fixes #1757)

Allows to download private playlists
[gamekings] Fix the test video checksum
Don't assume the 'subtitlesformat' is set in the params dict (fixes #1750)
Fix filename extension leaking to json filename

Makes writeinfojson behaving exactly as writethumbnail in case where filename contains mediafile extension.

Case:

video.mp4 converted to music.mp3 would yield music.mp4.info.json instead music.mp3.info.json or music.info.json
Update test_write_info_json.py
[livestream] Add an extractor for the original version of livestream (closes #1764)

The two versions use different systems.
[soundlcoud] Set the correct extension for the tracks (fixes #1766)

Some tracks are not in mp3 format, they can be wav files.
[youtube] Fix protocol-independent URLs (Fixes #1768)