Allow split build for all games except libkmahjongg dependencies.
Most of this is straightforward. Some more complicated changes are in 1. libkdegames: I needed to fix the headers <KgAudioScene> and <KgSound>, which did not refer to the right include location when installed. 2. kgoldrunner: Its CMake code may not depend on OpenAL and libsndfile anymore. KGoldRunner therefore now uses the new <libkdegames_capabilities.h> header and enables sound only if KGAUDIO_BACKEND_OPENAL is set. KMahjongg and KShisen are not done yet. I could not create a config-script for KMahjongg because CMake currently gets confused over exported targets in multiple source directories. (D'oh...) svn path=/trunk/KDE/kdegames/kdiamond/; revision=1294007