Merge pull request #361 from kaltura/widevineOnPage

Widevine on page plugin
IpadNative Controls demo page fixes
Docs: Improved native Controls demo, 

* adds support for single attribute based demo descriptions
Docs: increased player height
ServerSidePlaylist: Adds stub examples
ServerSidePlaylist: more stubs for serverSide playlist
removed openx demo ( was broken )
ServerSidePlaylist: Improved documentation for ServerSide Playlist
ServerSidePlaylist: grammar fixes
ServerSidePlaylist: moved player description lower in the page.
Merge pull request #368 from kaltura/ServerSidePlaylist

Server side playlist, just a documentation page update.
README: removed submodule licence line
Merge branch 'master' of git@github.com:kaltura/mwEmbed.git
Update TremorPrerollPostroll.qunit.html

use valid uiconf_id. 
added wgGetUrl helper, append port to URLs and override $wgLoadScript
Merge branch 'master' of https://github.com/kaltura/mwEmbed
Merge branch 'master' into 1.7.4_March_17th
bump version 1.7.4
bump 1.7.4