Remove obsolete KDevelop project file.

KDevelop no longer uses this format, and it's broken in more ways than
one anyhow (utilizing the non-existent autotools files for building
and svn for version control).
Remove executable bit from various images
Code formated.
Improved the checkbox implementation.
Better versions of the editor brush button images.
Fixed freshly unchecked boxes being in a wrong pressed state.
Minor code cleanup.
Implemented a gui1 radiobutton
Put it in place at the editor toolbar and the lobby preferences.
cb project update
update the respective .gitignore file with CodeBlocks's output files
Add C++11 override markers.
Merge branch 'master' of ssh://git.code.sf.net/p/wesnoth/code
Add new files to Xcode project
Do not optimize surfaces while building background
Premature optimization causes color channel swapping on systems that do not have the display format match the neutral surface format.