Allows coding the GUI without global functions which break
prototype-oriented coding, refs #5322, fixing the concern in 4b1297b328.
Supports stacked message boxes and removes the according workaround.
Change structree / civinfo switch-dialog code from 760a47335d to perform
the callback for page that actually registered the callback.
Ensure the parent that the callbackhandler is always called if the page
is closed.
Merge PopGuiPage and PopGuiPageCB following that choice, incidentally
leaving cleaner code.
Differential Revision: https://code.wildfiregames.com/D1684
Comments by: Yves, Vladislav, wraitii, leper
This was SVN commit r22676.
JSInterface_L10n.cpp from d6db5a466d,
JSInterface_Renderer.cpp and JSInterface_GUITypes.cpp from 4b1297b328,
JSInterface_VisualReplay.cpp from b830233498,
JSInterface_Game.cpp from 5f8be8e0c6,
JSInterface_Simulation.cpp from 921c5515a6,
JSInterface_Debug.cpp from d6cb9c845b,
JSInterface_Main.cpp from 486aec18d4, refs #4772,
JSInterface_Mod.cpp where it was incorrectly removed in af03c72f76.
Refs D1470.
Sort includes alphabetically, add recent Coding Convention macro
comments.
This was SVN commit r21789.
