Blender Git Loki

Fix T44685 - In grease pencil stroke editing, selecting points is offset by a few pixels

The problem was that it was aborting too early after stumbling across a point which
might fit within the bounds required. This commit improves the logic here to solve
this and a few other little bugs like that.

Disclaimer: There are still a few cases where it randomly ends up picking something
way off. However, this only seems to occur very sporadically, so it's hard to say
how bad the problem may be.