#43 Trimming the rectangle has more than one behavior

[Luiz Real]

When trimming a rectangle's corner using a line (for example) as a reference, the behavior of trimming is different depending on the references selected. If you select only the line as a reference, only one side of the rectangle's corner is trimmed. If you select nothing as a reference (i.e, use every element as reference), all the corner is trimmed.