Theme pack for editor

The Editor's user interface can be easily customized, replacing some or all of the images and icons. This feature is the implementation of theme packs - a special image pack and settings file which replaces the default UI elements with the pack's contents.

Structure
All themes have a structure:

themes/
 * /
 * theme.ini
 * img1.png
 * img2.png
 * icons2/
 * myIcon3.png
 * MyIcon5.png

Images can be placed into sub-folders which can make the theme folder more organized.

theme.ini - the theme config file, which defines the images which will be replaced in the editor.