bmesh py api: change .from_mesh() / .to_mesh() to be class methods of BMesh rather than functions in the module.

added example script which converts a mesh to a bmesh, edits and converts back again.

release/scripts/templates/gamelogic_simple.py

@@ -0,0 +1,17 @@
+import bge
+
+
+def main():
+
+    cont = bge.logic.getCurrentController()
+    own = cont.owner
+
+    sens = cont.sensors['mySensor']
+    actu = cont.actuators['myActuator']
+
+    if sens.positive:
+        cont.activate(actu)
+    else:
+        cont.deactivate(actu)
+
+main()