[Ohrrpgce] SVN: teeemcee/8283 spriteedit: Add Redo; rewrote undo to use a Frame ptr vector.

[subversion at HamsterRepublic.com]

teeemcee
2016-12-29 17:52:11 -0800 (Thu, 29 Dec 2016)
473
spriteedit: Add Redo; rewrote undo to use a Frame ptr vector.

Allocate up to 16MB for the undo history (hundreds of times more than before,
which was 32KB). I also doubled the size of the map editor undo history to
16MB, to match.

I got rid of the 'is_rotate' argument to writeundospr, since the only good
reason to skip rotate steps was when the undo history was very short.

Also tried to simplify the code a bit by fiddling with the icon colours
(added textcolor_icon)
---
U   wip/const.bi
U   wip/custom_udts.bi
U   wip/drawing.bas
U   wip/whatsnew.txt