OSMF SVN

PARB feedback: Allow MediaElement subclass constructors to have default params. This involved moving the ILoader param to the second param, and providing a default when no loader is provided. For subclasses (like VideoElement) for which multiple loader types are supported, the implementation now chooses the appropriate one based on the resource type.

Removed build warnings from several test projects.

Update references to MediaPlayerWrapper.

IMediaResource - > MediaResourceBase.
IURLResource -> Gone.

PARB changes: Modify MediaPlayer API based on PARB feedback. Change "durationReached" event to "complete". Update unit tests and sample apps.

Updating more samples to the latest API changes.

PARB changes: Refactor MediaError to use Error as a subclass. Update unit tests and sample apps.

PARB refactoring: Rename ViewTrait's dimension properties.

Updated sample apps to match new IPluginInfo signature.

Commit of traits refactored as classes instead of interfaces. A trait now has a public API for clients, and a protected API that implementors can use to hook into the workflow. Lots of additional changes:
* Merge spatial and viewable traits
* Merge load and download traits
* Merge play and pause traits
* Refactor MediaTraitType to hold strings (consistent with PARB)

Note that the composition layer is currently disabled (CompositeElements only support the Audio and Buffer traits). There may also be some bugs in the area of HTML support.