visualgst: Move inspector extensions to Inspector/Extensions.st

2013-06-18  Gwenael Casaccio  <gwenael.casaccio@gmail.com>

	* Inspector/Extensions.st: New.
	* Extensions.st: Move inspector extensions to Inspector/Extensions.st file.
visualgst: Add inspector view for contexts

2013-08-20  Gwenael Casaccio  <gwenael.casaccio@gmail.com>

	* Inspector/Extensions.st: Add ContextPart view support.
	* Inspector/GtkContextInspectorView.st: Dedicated view for ContextPart.