Draw tab color in white if the window appearance is dark. This happens to work for the main menu (it has a window!) as well as the context menu on a tab. Issue 6286.

Not every class was looked over, though.
Remove redundant declarations of dealloc in interface blocks.
Mark constructors of classes with instancetype instead of id.

Move source into sources/ directory. Delete a few unused images in the process and fix a reference to an Aqua image in FindView

Make metal tabs look nicer when colored. Don't color title bar, tabbar background unless there's only one tab. Also adds some ptylog statements to debug multimonitor setups

Adds colors to the tabs making them easy to distinguish.