Merge d2core/d2gui and d2core/d2ui

[gravestench]

We currently have two UI management packages, and no clear indication as to which should be preferred or what their differences are. We really need to merge these two packages into one package.

[juander-ux]

I can take this one, as I'm cleaning up parts of the ui anyways.

[juander-ux]

I saw that d2gui is only really used by the escape menu. The escape menu with the d2gui system looks over-engineered to me. We get automatic layouts but need to fix them anyways with spacers. Do we really need automatic layouts just to have a little easier time to add items to the escape menu? I'd rather remove the automatic layouts and have a simpler system. Any comments?

[gucio321]

I saw that d2gui is only really used by the escape menu. The escape menu with the d2gui system looks over-engineered to me. We get automatic layouts but need to fix them anyways with spacers. Do we really need automatic layouts just to have a little easier time to add items to the escape menu? I'd rather remove the automatic layouts and have a simpler system. Any comments?

also please note, that in fact escape menu shouldn't use text labels.
it should use sprites instead (they are enumerated in d2resource like EscapeOptions e.t.c.)