OSMF SVN

Fix inconsistency in NetStreamSwitchableTrait's storage of currentIndex (now it's consistently on the base class). Disable one specific unit test which is related to MockNetStream. (Note that this unit test works when running against the network.) Will fix later.

Fix for FM-165, the getter for currentIndex was removed from NetStreamSwitchable trait. Added it back.

1. Put TODO in CompositeMediaTraitFactory.as where IDownloadable is not supported yet
2. Add a comment to net/NetStreamDownloadableTrait.as to indicate that due to the nature of NetStream class, BytesTotalChangeEvent is not dispatched by the class.
3. Move dispatch BytesTotalChangeEvent to postProcess.

Adding support for IDownloadable to ContentElements:

* Introducting ContentDownloadableTrait.
* Adding bytesLoaded and bytesTotal getters to ContentLoader. The latter fires a BytesTotalChange event, that ContentDownloadableTrait listens to.
* Updating ContentElement to instantiate the new trait.

Extending Example player:

* Adding 'bytesDownloaded:' and 'bytesTotal' fields to the UI.
* Hiding/showing the fields according to the Downloadable trait being available or not.
* Added plumbing to update the values.

Changes to previous commits:

* DownloadableTrait: CTOR: removed 'target', for we want the trait to always be the dispatcher of its own events.
* SoundDownloadableTrait: made class internal, removed 'target' from CTOR, added listener for Sound's OPEN event to ensure getting 'bytesTotal', and changing events to be dispatched on changing the value from/to NaN.
* BytesTotalChangeEvent: added 'clone' method.
* MediaPlayer: added code to start the downloadable timer on the Downloadble trait being added/removed. At 'onDownloadTimer', now also dispatching changes from/to NaN.
* BytesDownloadEvent: renamed to BytesDownloadEventChange, and made it about bytes downloaded only, using our newValue/oldValue convention. Added 'clone' method.

1. IDownloadable support
2. PluginSample is integrated with IDownloadable.as
3. unit tests fix up

Dual-buffering example: Reduce buffer size on pause.

Fix for bug FM-108 Local progressive URL not working with MediaPlayer. Modified the URL class to handle relative paths correctly.

Minor API change: Use Vector not Array for MediaElement.get traitTypes. Approved by dev team. Should be no impact to sample apps, unit tests, or test apps.

Fix brace.

Removing old prototype code.