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.
Previously the argument order for Margins was (left, top, right,
bottom). To make it more familiar and closer to how CSS does it, the
argument order is now (top, right, bottom, left).
Applications previously had to create a GUI::Menubar object, add menus
to it, and then call GUI::Window::set_menubar().
This patch introduces GUI::Window::add_menu() which creates the menubar
automatically and adds items to it. Application code becomes slightly
simpler as a result. :^)
This is not only easier to comprehend code-wise and avoids some function
overloads, but also makes resizing the board while preserving game state
*a lot* easier. We now no longer have to allocate a new board on every
resize, we just grow/shrink the individual row vectors.
Also fixes a crash when clicking the board widget outside of the drawn
board area.
