Fixed Issue 162:  	 Drawing regular shape (rectangle) causes crash gp_Dir doesn't like having no length. We don't seem to handle Open CASCADE's errors too well. Anyway, this change stops gp_Dir being constructed with no length, in this case.
Fixed Issue 162:  	 Drawing regular shape (rectangle) causes crash
gp_Dir doesn't like having no length. We don't seem to handle Open CASCADE's errors too well.
Anyway, this change stops gp_Dir being constructed with no length, in this case.
danheeks/heekscad,danheeks/heekscad,danheeks/heekscad,danheeks/heekscad