This command line option is useful for KWin in embedded use case. That
is when KWin is just used as a compositor for one application instead of
a complete desktop environment. In such a setup global shortcuts are not
wanted and interfere with the application. E.g. one does not want Alt+F4
to close the window, that would render the system unusable.
This change introduces a command line option and disables the following
event filters and spies:
- global shortcuts
- modifier only shortcuts
- terminate session
- virtual terminal switching
- screen edges
KGlobalAccel still gets inited, otherwise the (non-functional) binary
would be launched when KWin registers it's global shortcuts.