Review changes made for Issue #53 CMake

I've made all the CMakeList files the project needs. I managed to get the project to build, compile and install. However, when I try to run the qmlscene ui/main.qml, it can't seem to find the directories where the plugins are installed. Could you have a look?
This is used to copy over the beru.desktop file into the build directory, and, for some reason, there has to be another copy called beru.desktop.in, but I'm not sure what the .in file does. In any case, it should work without this line second line (the ${DESKTOP_FILE}.in)