Having the return key sometimes press the equal button when nothing is
focused and press a different button when there is focus felt confusing.
The equal button is still able to be focused for the tab cycle to have
something to go to in order to jump out of the textbox but no other
keypad button can be focused now.
This allows for typing [8] instead of [8, 8, 8, 8] to specify the same
margin on all edges, for example. The constructors follow CSS' style of
specifying margins. The added constructors are:
- Margins(int all): Sets the same margin on all edges.
- Margins(int vertical, int horizontal): Sets the first argument to top
and bottom margins, and the second argument to left and right margins.
- Margins(int top, int vertical, int bottom): Sets the first argument to
the top margin, the second argument to the left and right margins,
and the third argument to the bottom margin.
