Total redesign of lxqt-config-input using LxQt::ConfigDialog and integrate lxqt-config-mouse.
Try to integrate lxqt-config-appearance with lxqt-config-mouse so we can select cursor themes in lxqt-config-appearance, too.
Rename lxqt-config-mouse to lxqt-config-cursor to reflect what it does.
Remove unnecessary desktop entry files and do some makefile cleanup.