UFO:Alien Invasion Code

* crushed png files

* reverted 'removed icons and buttons that are part of the icon pack'

* This reverts commit 0069eab13c03896625189628c762040d1f983b16.
* this wasn't for the master, but for the 2.4 branch

* removed icons and buttons that are part of the icon pack

* i also had to remove the LICENSES entries to make the commit hook happy - grab the license information either from this commit or from master

* rescaled the pen icons

* Rescaled pen icons to power-of-2 resolution (64x64) to eliminate in-game scaling artifacts without changing the actual textures but just their canvas sizes

* New pen icons, new scroll_bottom and scroll_top icons, replaced tab_map icon with better version

* use button, use real icon