OSMF SVN

Fix for FM-1310 ( http://bugs.adobe.com/jira/browse/FM-1310 )
- updated mixer code which is now intercepting all events from chunks/fragment sources and forward them to NetStream

NOTE:
- we have some unused classes in our codebase ( expect a clean-up change list)

Added missing rolling-window updates ( support for windowDuration )

Fix bug FM-1288 (http://bugs.adobe.com/jira/browse/FM-1288)
- the bug has been fixed in a previous change list
- this change list contains only an integration tests for this bug

Fix FM-1301 bug ( http://bugs.adobe.com/jira/browse/FM-1301 )
- we were trying to close an unconnected URLStream
- added two integration tests (multipleSeek_SwitchBeforePlay and multipleSeek_SwitchAfterPlay)
- updated playLegacyHDSSBRWithLiveDRM tests to account for longer DRM library download

Fix for FM-1275 ( http://bugs.adobe.com/jira/browse/FM-1275)
- refactoring of the integration tests to be more reliable

Integrate of PARB review over LBA
- renaming MediaItem class to StreamingItem
- renaming MediaItemType class to StreamingItemType
- various properties and methods updates (AlternativeAudioTrait, AlternativeAudioEvent, MediaPlayer)
- unit tests and integration tests updated

NOTE: OSMFTestNew still not compiling.

LBA updates
- fix FM-1293 bug (http://bugs.adobe.com/jira/browse/FM-1293)
- add legacy integration tests for HDS

New unit /integration tests. Running them requires internal resources, we'll add them later.