Lines attached to connection points jump when shape resized

[iwbnwif]

A line connected to a connection point may jump to a different connection point when the line is resized.

This is difficult to debug because the line mod routines are called on every mouse move (even when no update is required - why!).

However, it looks like the problem may be in wxSFLineShape::GetModSrcPoint() and wxSFLineShape::GetModTrgPoint() where a call is made to pSrcShape->GetNearestConnectionPoint( nModPoint ).