keymap cli tool: add StyledEdit attributes

[humdinger]

This is hrev31133.

It'd be nice if keymap's dump function (-d) would add the StyledEdit styles attribute for fixed font formatting. Just that little bit of extra Haiku convenience... :)

[axeld]

The keymap utility currently only dumps to the terminal, not a file, so it cannot write any attributes; this could be changed of course.

[anevilyak]

I thought it only dumps to the console if the -d option is given? At least its code appears to have the ability to write it to a BFile as well (see Keymap::Save()).

[axeld]

Keymap::Save() stores a binary keymap - it wouldn't make much sense to open that one with StyledEdit :-)

Anyway, implemented in hrev31196.