Increase version to 0.4.0 for upcoming release.
 * Overlays now also use the alpha value of the client. refs #822
When using scons, if the fifechan module is build the files for it will now be also installed to python.
Fixed compiler warnings and an multicell pathfinder bug.
Added to fife_tests an Heightmap Test and the corresponding Tileset.
Merge branch 'master' into cegui_0.8