OSMF SVN

Fix FM-970. There are two issues that the fix tries to address:

1. Calling the remote subscribe method on each DVR stream, and also the streamName for MBR case comes from the streamItems instead of the resource url.

2. To support MBR, the DVRCastNetLoader.as needs to have the createSwtichManger method implementation. The best way to do it to derive the class from RTMPDynamicStreamingNetLoader class instead of NetLoader class.

Created tag neon-sprint3-stable.

Fix compile error (Flex 4 only).

Eliminate compiler warning related to log statement.

Fix ExamplePlayer UI for Flex 3.0.

Fix FM-990: Loading images always requests a crossdomain file. The fix is to add a "checkPolicyFile" param to ImageLoader's constructor, with a default of true. To avoid the crossdomain request, just set this param to false. The downside of setting it to false is that you'll get a security error if the application attempts pixel-level access of the image.

Add PreloadingProxyElement to ExamplePlayer, to demonstrate how a proxy can preload a VideoElement within a SerialElement and make it seekable prior to the playhead reaching that child of the SerialElement. Helps demonstrate a solution for the issue raised in FM-952, in which it's not possible to seek across subclips within a SerialElement. Modified existing AsynchLoadingProxyElement so that it could serve as a base class for the new proxy.

Fix FM-1014: AudioeElement does not play m4a over http.

Fix FM-953: MediaPlayer lacks method to expose DVR recording state. Add unit tests. Also fix missing clone call on DVREvent.

Fix for FM-983