OSMF SVN

Partial fix for FM-383: ProxyElement needs to dispatch traitRemove/traitAdd event pairs when the proxy adds or removes a trait that also exists on the proxied element.

Sync with latest layout API changes.

PARB feedback: rename LayoutProperties to LayoutRendererProperties.

PARB feedback: rename LayoutRenderer to LayoutRendererBase, rename DefaultLayoutRenderer to LayoutRenderer.

Updating source path to control bar plugin.

Moving ControlBarPluginSample and Test into the plug-ins folder.

PARB feedback: taking out 'media' references; renaming measureMedia to measure, and updateMediaDisplay to layout.

PARB feedback: updating sample to use measureWidth and height.

PARB feedback: renaming LayoutRenderer.targets to hasTarget.

PARB feedback: adding ASDocs to LayoutRenderer.measuredWidth and height properties.