[better mouse/kb & some UI, new hollow monster]

Couple of small changes, both visible and less visible, and a new 'hollow' monster -

UI/user input:

• using mouse long press for panning the view is hopefully usable/fixed - it doesn't require the user to hold the cursor static with no movement in order to accept the long button press - thus invoking long press more easily

• you can now also zoom in/out using Ctrl+ keys

• (using Ctrl+ to move always turns on fast mode)

• use Alt+Enter to go windowed/fullscreen

• added font scaling (see Settings) for messages in the game log (only, for now..)

Game/feedback/messages:

• message when room is empty

• sleeping status of monsters is messaged

• (next no pickup message, if used)

• loot dropped from monsters can fall farther from them

New monster: `a[c] hollow`[/c]

• you might occasionally encounter a 'hollow' - your previous incarnation wandering the dungeon as a phantom around the level you perished on

• the hollow will have all of your previous equipment and items, but not all of it could be retrieved once you slay it

• it can spawn ~on the level you died on, with previous XP and HP, but won't be able to use/wear any equipment or items yet

• there is ~ 1:10 chance of a hollow to appear on within +/- 1 level where it originally perished, last 5 demises are recorded (if any); a record is discarded when a hollow spawns

~o./