* Fix for the aspect ratio not being properly set when screens have
different aspect ratios.
* Minor fix for makeCurrentImplementation being called directly instead of
makeCurrent() causing the owning thread pointer not being tracked
* Fix for osglauncher so that it sets its update text regions to DYNAMIC to
prevent multi-threading issues.
as osg::GraphicsOperation. Unpdated parts of OSG depending upon these.
Added a virtaul bool valid() method to osg::GraphicsContext to allow apps to
test whether a valid graphis context has been created or not.
added frame stamp updating and update traversal to osgViewer::Scene/Viewer.
Updated osgcamera example to use new Viewer API calls instead of using local
rendering calls.
the names of the operations to be logged for stats purposes, or used when
do searches of the operation list. The keep member variable tells the graphics
thread run loop wether to remove the entry from the list once its been called.
