Internal changes in the libraries

I did a couple of major internal changes to the libraries of icons and cursors. Hopefully, I did not break anything... If anyone spots an error related to the libraries, please post it in this thread.

The changes include:

• Inclusion of a readme file with set description and licenses to each zipped set.
• More effective storage -> more space for icons and cursors.
• Minor changes to layout of set pages.
• Authors cannot rate their own sets anymore and rating is now more graphical.
• There are links from set to its icons or cursors and also back.
• Set creation should be simpler.
• Descriptions of set, icons, and cursors follows the forum formatting rules.