Removed common object from make system
Merge branch 'master' into gui
Applied changes of Makesystem
Solved invalid Application ID Warning
Port to SDL2
Merge branch 'master' into gui
Removed SDL from test target
Port to SDL2
Removed SDL from test target
Seperated Joystick Error and solved Race

        - Race condition on joystick thread destruction solved
        - Switch back to SDL1 because of Event Bug
Solved Race in Comm Thread destruction
Enhanced closing of program

        - Program now closed correctly with CTRL-C and Window closing
Merge branch 'gui' of https://github.com/steup/mobilePI into gui

Conflicts:
	include/JoystickError.h
	src/Joystick.cpp
Small fixup
Merge branch 'master' into doc
Added missing DOC Variable in Makefile