The KGlobalAccelD which gets created by KWin needs a plugin for the
platform specific parts. This change introduces such a plugin. It's
linked against kwin so that it can integrate with the core.
On enable the plugin registers itself in the InputRedirection and
GlobalShortcutsManager checks the plugin whether a shortcut got
triggered.
As the loading of the plugin must happen after InputRedirection is
fully created a dedicated init method is added to InputRedirection.
REVIEW: 124187
A new GlobalShortcutsManager is introduced which is responsible for
holding the registered shortcuts and triggering the matching action.
The InputRedirection checks with the GlobalShortcutManager whether a key
press event triggers a global shortcut and stops processing the event in
that case.
At the moment the GlobalShortcutsManager only supports the very basics
for KWin internal usage. External applications can not yet make usage of
the global shortcut system inside KWin.
