audio: clamp overflowing values
Merge branch 'master' into audio
jobmanager: add jobmanager and integrate it into engine
jobmanager: fix header guard typo
jobmanager: add this-> to members and add comments
audio: rename ResourceLoader to InMemoryLoader
audio: basic dynamic audio loading is working
audio: add comments, small fixes
Convert `doc/` to markdown
envine: converted the core engine to object oriented gnampf
engine: grouped all engine shit to object oriented fu
testing: rendering any building implemented. change with ctrl-scroll.

To quote valgrind:
More than 10000000 total errors detected. Giving up.

Yes, it's full of errors and dirty hacks in the test,
but at least we got buildings now.
Now follows great optimisation work.
convert: enabled all media file conversion by default
ci: try to preserve path for sudo, clang can't be found otherwise
test: removed ; for passing pedantic Werror compiling
ci: export absolute CC and CXX paths as travis still fails with sudo
status: added all buildings and middlemouse scrolling features
Merge branch 'audio' into jobmanager

This brings background loading for audio files.

Conflicts:
	src/CMakeLists.txt
	src/audio/audio_manager.cpp
	src/audio/audio_manager.h
	src/audio/resource_loader.cpp
	src/audio/resource_loader.h
	src/engine/audio/in_memory_loader.cpp
	src/engine/audio/resource_loader.cpp
	src/engine/engine.cpp
	src/engine/engine.h
	src/engine/init.cpp
testing: using dynamic background audio loading
util/fps: properly initialize variables for fps counter