Began improvements to columns API by splitting the Columns() function#913

Merged

ocornut merged 1 commit intoocornut:masterfrom ggtucker:master

Aug 20, 2017

+200-90

Commits on Nov 14, 2016

Began improvements to columns API by splitting the Columns() function into BeginColumns() and EndColumns() and adding additional flags. The columns data still needs to be placed into a stack.
ggtucker
committed