Blender Git Loki

UV: tweak face select behavior

When the mouse cursor is inside the UV face,
extend the selection threshold.

This means when zoomed in, a face can always be selected when the cursor
is inside it.
In the case of multiple overlapping faces - the face with the closest
center is used.

Cleanup: move UvNearestHit.ob assignment in find nearest functions

This makes it possible to pass multiple hit arguments.

Also rename 'hit_final' to 'hit', since there are no longer a local
'hit' variable defined in these functions.