Major milestone: keys are now tracked via the player inventory, and lockdefs are fully functional.

Note: HUD and statbar key displays are non-functional in this revision, and you will lose keys if you save and reload the game. Temporary regressions due to incomplete transition - skip this rev for gameplay purposes.

git-svn-id: http://mancubus.net/svn/hosted/eternity/trunk@2599 86ba831e-150c-0410-ab35-e06eaae15ed9
* Store cardNames in GameModeInfo
* Use inventory to query for keys in cheat, HUD, and statbar modules
* Removed player->cards[]; saving/loading inventory is still INVENTORY_TODO (see p_saveg.cpp)

git-svn-id: http://mancubus.net/svn/hosted/eternity/trunk@2600 86ba831e-150c-0410-ab35-e06eaae15ed9