* Use single static buffer instead of each overlay having its own (its only used in the material system thread).
* Improved readability by using ternary operators and c++ style casts.
* Fade notify text by a fixed amount regardless of the frame times.
* Implement Valve's 'lerping' animation for text when entries fade away and expire.
* Don't run/push/remove anything if 'con_drawnotify' is disabled.
Run all Cbuf_Execute calls in the main thread. This should fix every problem related to (but not only):
* Connecting to server while RUI dialogue is still open.
* Connecting to server while in an active game.
* Running 'weapon_reparse'.
