Support "newstyle" Youtube playlist IDs.

Many playlists reported by Youtube now have the form like in:

    http://www.youtube.com/playlist?list=PL520044A3524F5E5D

where `PL` is prefixed to what youtube_search used to use as playlist IDs.
So, we discard the `PL` with a regular expression and only get the `520044A3524F5E5D` in the case of the playlist of the
example.
add missing test
bump version to 0.1.3
The duration attribute for each video is now available.
The specs were failing on playlist retrieval. Playlist data was being retrieved over https. 1.9.2's HTTP call was returning 'certificate verify failed'.  https is not actually needed and the url has been changed to http. Specs now pass.
Merge pull request #4 from aantix/master

Duration property now available.
bump version to 0.1.4
add jim Jones to contributors
make tests less brittle
refactor duration fetching
add raw for custom needs
bump version to 0.1.5
Added an embeddable property. Specifies whether a video may be embedded on other websites.
add update fixtures task -- breaks specs...
Merge branch 'aantix-master' into merg
revert to old xml
add proper specs
bump version to 0.1.6
add embeddable to readme
searching playlists