Previously, node selection made no distinction between a frame node and
other nodes. So a frame node would be selected by their whole rect or
center (depending on box/lasso/circle select). As a consequence of this,
box and lasso could not pratically be started inside a frame node (with
the intention to select a subset of contained child nodes) because the
frame would be selected immediately and tweak-transforming started.
Circle selecting would always contain the frame node as well (making
transforming a subset of nodes without also transforming the whole frame
impossible).
Now change selection behavior so that for all selection modes only the
border [the margin area that is automatically added around all nodes,
see note below] of a frame node is considered in selection. This makes
for a much more intuitive experience when arranging nodes inside frames.
note: to make the area of interest for selection/moving more obvious,
the cursor changes when hovering over (as is done for resizing).
note: this also makes the resize margin consistent with other nodes.
note: this also fixes right resize border (was exclusive instead of
inclusive as every other border)
Also fixes T46540.
1995aae6e3