common: added common module and AbstractServiceImplementation
application: added common module
controls/VirtualJoystick: added single axis support
application: made use of AbstractServiceImplementation
application/ApplicationCore: Item is not necessary anymore
pathview/GLCamera: small improvements to documentation
halremote: made use of AbstractServiceImplementation
service: replaced QQuickItem by QObject
videoview/MjpegStreamerClient: removed dependency to QQuickItem
pathview: made use of AbstractServiceImplementation
Revert "application/ApplicationCore: Item is not necessary anymore"

This reverts commit 142a0b3807c74ab05cd841eecab4bda651ed4d20.