[CB-1593] Fix for media not playing on the first try due to 'ArgumentException'
[CB-1593] Fix for multiple callbacks when playing a media file
update JS
update version number in various files
Merge branch 'CB-1593' of git://github.com/bennmapes/cordova-wp7 into 2.4.0Prep
Merge pull request #2 from purplecabbage/2.4.0Prep

2.4.0 prep