MacOS decorator issues

[MagnetarRocket]

While the included version of the mac Decorator complies and works, there are two major issues with it:

1. The resize gadget is not shown, which is a very important thing in haiku as there's not much alternatives (keyboard shortcuts or not) to the resize handle(s)

2. There is no visually elegant way to truncate the titlebar when needed:

Visual references from MacOS 9.0.4 (That shows the proper behavior for the two mentioned issues):

A interactive example can be found at https://infinitemac.org/2000/Mac%20OS%209.0.4

[MagnetarRocket]

Also there should be a major refactoring of the code in order to be included with the main package repository of haiku.

[MagnetarRocket]

Another one is that this decorator does not play nice with window stacking feature of haiku. Open windows that are stacked only show the last active app as the whole window.