gui - Super minimal, rock-solid foundation for concurrent GUI in Go.

	Commit message (Expand)	Author	Age	Files	Lines
*	lay/strain: refactor data structureslayout2	Sam Anthony	4 days	1	-50/+66
*	lay/strain: wrap Solver in private struct	Sam Anthony	4 days	1	-70/+80
*	lay/strain: replace Solver mutex with channels	Sam Anthony	4 days	2	-106/+226
*	lay/strain: add default constraints to Solver	Sam Anthony	12 days	2	-27/+80
*	lay/strain: use synctest	Sam Anthony	12 days	1	-33/+37
*	lay/strain: remove TODO	Sam Anthony	12 days	1	-1/+0
*	lay/strain: simplify Solver internal synchronization	Sam Anthony	12 days	3	-124/+135
*	lay/strain: represent rectangles as (origin, size)	Sam Anthony	12 days	3	-25/+131
*	fix compiler errors	Sam Anthony	12 days	1	-4/+4
*	create lay/strain package	Sam Anthony	13 days	5	-0/+408