Reassign obnoxious global shortcuts

Shortcuts like 'N' for Next Actions and 'W' for waiting are bad, because they
are movement commands, and people can use them by mistake.  I should try to only
clobber commands which nobody will be using in these windows anyway.
Don't clobber '/' in Contexts view

It's natural for people to want to search for a context by name.

'#' is a much better choice; I can't think why there would be more than one
instance of a context name, or why someone would want to jump to the next one.