Fix typo
Add dependency install commandline for Ubuntu
Include improved sauer2_7 level by @sauer2 (#59).
Fix SMC crashing on save/load due to missing player_posx.

That one is only saved for the active level, not for other ones
(read inactive sublevels).
Merge branch 'release-2.0.0' into devel
Fix unexpected behaviour with CMake < 2.8.10.

These old CMake versions were unable to parse the URL for CEGUI.
Merge branch 'release-2.0.0' into devel