Fix invalid set of the variable

Changed naming of the mixers to get rid of umbiguity as outputs are actually going to be driven by io, not fmu
Implemented automatic lookup for the .aux.mix file if it exists

GPS driver: Add missing wall clock setup for MTK GPS modules

Adding a new base class to remove a lot of boilerplate code, no
functionality changes

Move all unittests to cmake

Multitables script fixes

The script still works with python2, I also added a file ending

Multitables v3

Conflicts:
	src/modules/systemlib/mixer/multi_tables