minor improvements
improvement for Travis-CI
improve CMake file
add CMake files for Ogre, lualib50, vorbisfile
adjust CMakeLists.txt for Engine
switch back to CMake for building the engine
add missing break statements in Sound class
add missing break statement in MediaWave class
initialize all members of Application class in constructor
better initialization of members of Camera class in constructor
fix Lua return value of Dusk::Lua::GetAnimated()
fixes for Dialogue, Scene and IDNotFound classes
fix uninitialized member in Light class
another adjustment for CEGUI 0.7

(See <http://www.cegui.org.uk/docs/current/porting6to7.html>
 for more info on the breaking changes between CEGUI 0.6.x and
 0.7.x.)