Steamtech UI fix

More generally, "any UI that changes separator width fix and some fancy math". Levelup dialog now contains much less magic numbers and instead uses the full power of Setup UI. All other dialogs touched mostly involved really small fixes because they're p basic.
Seriously. It was a hassle. People, write flexible code.

Well, here goes.

I really should've tested it more. Seems like cherry-picking commits from my big branch missed some important fixes later on.

So sorry

So, so sorry

removeEffectsFilter tweaks

There's a great function, Actor:removeEffectsFilter, which doesn't get used that often. Partly because of the fact that it never was quite powerful enough to be used. This commit adds a couple of extra checks for it, and makes staple "strip sustains" and "strip effects and sustains" functions, too.
I only converted Wild and Primal infusions because I don't feel like testing about 10 talent trees that currently contain interactions with random effects. The original contributors of that trees may decide to switch to use the new interface, though, and addon developers are welcome as well.

Removable egos

Recently there was a talk on IRC how sweet would it be to be able to strip egos from an object. This achieves just that, keeping a list of egos at each object, too!
As a nice bonus, it showcases its capabilities by converting Imbue Item and Reshape Weapon/Armor to slap egos onto objects (and in the second case, to strip them from objects, too).
Randarts now have egos, too, and even randart stat powers are hoarded together by the name and converted into egos. Overall it's pretty sweet.
Of course, this is not limited to objects in its applications. Imagine: SHAPESHIFTING ACTORS.

Callback improvements

Some touches on the callback system:
- callback adding/removing is factored out so that the same loop isn't just written everywhere;
- priorities can now be specified for callbacks (default 0), callbacks with lower priorities get called first. (By a popular IRC request.) Of course this involves sorting but measures are taken to do actual sorting as rarely as possible.
(As a side-effect, callback-order is now well-defined, being sorted by type ("effect", "object", "talent") and implementing object (taking its .name or tostring()).)
- sustained talents can now be made to behave like passive ones in terms of callbacks, by specifying passive_callbacks=true in talent definition.

Fix UI left, right, etc. calculations

While working on statusbox, I've discovered that:
- absolutely everything dependent adds self.ix, self.iy twice. or thrice. this was masking top= bug, for example.
- right=ui sets right to ui.x, which usually sets an object flying to the opposite side of the dialog,
- top=ui sets top edge to be equal to the top edge of the ui, which is probably not what's desired (see left=)
- bottom=ui has similar problem to right,
- hcenter=ui sends a ui element flying half a dialog width to the right,
- vcenter=ui, likewise,
- and hcenter_left=ui I didn't understand what it's supposed to do.

This commit fixes all of the above, sans the last, and also adds 3 pixels of padding between everything to compensate for buggy yet sometimes desired previous results.

Redisplay fix

Calling redisplay() multiple times per turn is notorious for causing lag. The worst offender is probably Smoke Bomb, and it just got stripped from Creeping Dark.
This commit introduces a new scheduleRedisplay method, which uses little-known feature of game:onTickEnd to ensure that a redisplay would only get called once per this tick, not causing any frame drops.

LevelupDialog status box

Many users have expressed their frustration that appears when clicking too fast on a talent or stat to level it up pops up a message, forcing them to click "Ok". This commit adds a simple status line on top of the window, always clearly visible, that communicates these short messages in aesthetically pleasing colours. For important messages (e.g. the player somehow created an impossible talent loadout), the modal dialog usage was retained.