[with-nrepl] Command to switch repl namespace

[hlship]

It would be very handy to replicate some of the Emacs nREPL commands.

A very useful one exists that switches the repl buffer namespace to match the current editor's namespace (which requires parsing the (ns) block).

An improvement over Emacs might be to keep a recent history of previosly selected namespaces and have a popup appear to select the namespace. You could actually mix the two: raise a popup where the first/default selection is the current namespace from the editor, and the rest are recently selected namespaces.

For extra credit, include the doc-string of each namespace that can be selected.

Thanks for all the work on this; it's rough going right now, but I'm hopeful it will all come together some day soon.

[emestee]

Thanks for all the input, and I will most certainly implement this.

[MattVane]

+1 bump!