Cleanup: Resolve HKEY conflict

Both the MS headers and blender headers define the HKEY
which gives all kind of inclusion order issues.

This diff renames all *KEY constants to EVT_*KEY to resolve
this conflict.

Reviewed By: brecht , dfelinto

Differential Revision: http://developer.blender.org/D7164

source/blender/editors/transform/transform_input.c

@@ -476,8 +476,8 @@ eRedrawFlag handleMouseInput(TransInfo *t, MouseInput *mi, const wmEvent *event)
   eRedrawFlag redraw = TREDRAW_NOTHING;
 
   switch (event->type) {
-    case LEFTSHIFTKEY:
-    case RIGHTSHIFTKEY:
+    case EVT_LEFTSHIFTKEY:
+    case EVT_RIGHTSHIFTKEY:
       if (event->val == KM_PRESS) {
         t->modifiers |= MOD_PRECISION;
         /* shift is modifier for higher precision transforn */