Application launcher on META key

[Eike Hein]

Hi,

so we've got this long-standing awkwardness that users generally
expect the Meta (aka "Win") key to open the application menu,
which is how it works on Windows and nearly all of the competing
Linux DEs, but isn't easily configurable in Plasma because we
don't support modifier-only shortcuts.

Plenty of distros therefore patch around, or ship a solution
like ksuperkey which maps a press+release event pair of meta
to Alt-F1.

I'm thinking it would be an improvement if we find a proper
solution we can ship upstream, to avoid downstream reinventing
the wheel yet again.

Thoughts? Any good implementation ideas?


Cheers,
Eike