Remove "templates-admin"

[Nico Knoll]

Hey,

I think it's time to remove "templates-admin". In my opinion the shared functionalities which are still used by Reno and Default Admin Theme should be put in a separate plugin ("AdminTheme") or a core class ("AdminTheme.php") and the old "templates-admin" should be removed.

To prevent that No admin theme is installed there should be a check if you try to uninstall an AdminTheme. And AdminThemeReno shouldn't have DefaultAdminTheme as dependency anymore but only "AdminTheme" class. 

This just makes more sense in my mind and prevents questions like this (which are completely understandable): https://processwire.com/talk/topic/10329-why-admin-theme-is-in-2-folders/ and questions about the old theme randomly popping up.

As Ryan wants ProcessWire to be usable without AdminTheme, too, it's probably the better way to put the stuff in a module (as mentioned above) which can't be uninstalled (unless you know how to force uninstall modules).

Please put this on the list for 2.7...

Thanks,

Nico