merge build_make_clean.sh into build_desura.sh
build_desura.sh: move compile code into 2 functions, one for cef and desurium each.
build_desura.sh: move some code around.
also "cd -" appeared to echo our current dir, "pwd" like. Use cd ../
build_desura.sh: now we can make clean for desurium and cef seperately.
build_desura.sh: implement separate compile_desura and compile_cef
build_desura.sh: only print that we can run desura if everything is compiled.
build_desura.sh: fix argument passing for compile options
build_desura.sh: fix cding, exit status and do some cosmetical changes.
build_desura.sh: implement rebuild commands which do a clean build. Fix argument passing.
build_desura.sh: more fixes/cleanups. Implement "help" argument.
install_script.sh: instead of removing the entire install dir on make clean, remove only files of the respective target.
build_desura.sh: fix script. Be more clever when suggesting what is still missing to run Desura.