[Ohrrpgce] SVN: teeemcee/8963 Reenable and rewrite mouse support in menus.

[subversion at HamsterRepublic.com]

teeemcee
2017-07-03 21:18:05 -0700 (Mon, 03 Jul 2017)
444
Reenable and rewrite mouse support in menus.

(Yikes, it's been 4 years since James disabled his first attempt!)
The difference is that this time, hovering the mouse over a menu item
highlights it (setting .hover) instead of selecting it.

This is blanket-disabled in Game. I'm not sure whether we want the mouse control
in Game to be per-MenuDef or per-MenuState or global (and overridable when
in a debug menu, etc), and how that should work.
---
U   wip/common.bi
U   wip/common.rbas
U   wip/menus.bas
U   wip/menus.bi
U   wip/udts.bi