expose width/height as ExampleBrowser options.

suppress lack of 'site' support message in MJCF importer
suppress lack of 'plane' visual support in urdf/sdf import
getBodyName default to "" to avoid breaking cloudsim
expose bodyName when requesting body info (sdf/mjcf import)
pass optional "options" string to pybullet.connect method. this can be used for --opengl2 flag in GUI mode (or other flags)

examples/Importers/ImportMJCFDemo/BulletMJCFImporter.cpp

@@ -1026,6 +1026,11 @@ struct BulletMJCFImporterInternalData
 			{
 				handled = true;
 			}
+			if (n=="site")
+			{
+				handled = true;
+			}
+
 			if (!handled)
 			{
 				logger->reportWarning( (sourceFileLocation(xml) + ": unknown field '" + n + "'").c_str() );