Feature request: Tween groups and group actions

[ivan-mogilko]

This request is following some conversations, both related to a use of the Tween module, and other game engine related things.

Often you need to distinct groups of objects of varied types, and perform an operation on all of them. One good example is pausing and unpausing. A user might want to pause all the tween effects in the room, related to the gameplay, while keeping all the menu/gui effects and animations running. One approach would be to distinguish by an object type, but sooner or later someone will run into a situation where this won't do.

My proposal is to introduce "tween groups", where group is identified either by a number or a string. The group is passed either as an extra argument in a function that starts tween, or there are special functions that add/remove particular tween from/to a group, e.g.
SetTweenGroup(int tween_id, int group);, where passing group = 0 would mean basically no particular group.

Afterwards, you could have group actions, like PauseTweenGroup(int group); and UnpauseTweenGroup(int group), and anything else what is useful.