sets initial playback position to the earliest common media time for audio and video
updates initial time adjustment logic so that the time can be moved backward as well as forward
fixes ABR switch for multi-period mpds
Merge pull request #295 from MSOpenTech/development

Contains fixes for calculations of initial playback position
compares streams id's instead of streamInfo objects in qualityChanged event listeners
Merge pull request #299 from MSOpenTech/development

Fixes ABR switch for multi period
Added default document to web.config
Added dash.debug.js
Extended DRM support

* Adding Widevine support.
* Extending PlayReady support with optional CustomData.
* Adding option to override protectionData (including laUrl, cdmData &
license request headers) when instantiating the player.
* Moved parsing of CDM message into respective DRM license acquirers.
* Initial fix for Chrome 38 (when chrome://flags/#enable-encrypted-media
is set).
Extended DRM support in Chrome

Using MediaKeys.create() promise when available.