Overhaul keymapping experience

[chaorace]

Currently, we offer only a few options for key bindings and the majority are completely hardcoded. We need to reimplement so that the majority of binds can be configured from an in-game UI. This feature won't be a main focus until more pressing issues like #514 and #271 are resolved, probably post-beta release

[chaorace]

See issue #64 for related discussion, which this ticket absorbs, for related discussion

[JHCD]

Hi Chris,
some of the bindings are changeable in the game already.
Do we have a chance to change them? Select option in CQUI-Gui -> Mapping in Civ GUI is changed?
Then we only have to build a gui for the "extended binding".

I didn't use any key bindings because of using a tablet.

[chaorace]

I'm only concerned with bindings introduced by CQUI. What you're suggesting is already what I had in mind from the outset.