[WIP] actions: add Tagline command

[josephholsten]

This is totally not ready to merge. The desire of this is to replace the ~/.de/tagline with a command which can live in ~/.de/startup. It doesn't do that yet, and it has other problems besides.

• ResetTagline should use the value from Tagline instead of getDefaultTagline
• Tagline should accept args containing a space, eg Tagline:Foo Bar. Perhaps quoting/escaping (ugh)? Can we just rely on startup to use complete lines, and use selection for manual execution?

[driusan]

Colons get replaced by space (unless they're escaped with a backslash) to make it possible to have spaces in arguments to executable words in the tagline.

I think that the appropriate behaviour for the startup script should be to execute lines one at a time as you suggest, even if there's spaces, but I'd have to look at the code to see if that's currently the case.

[josephholsten]

looks like a ~/.de/startup file of:

Tagline:Save Discard Cut Cupy Paste Undo Exit Shell a+ a-
TermWidth:72

sets the tagline to the entire string correctly, and still correctly uses the TermWidth command.