Fix keybinding highlighting
Fix nrepl-selector key binding

Previously C-c M-s was bound to `nrepl-select`, which does not exist.
You'd get this error message:

> Symbol's function definition is void: nrepl-select
Merge pull request #351 from miikka/bind-nrepl-selector

Fix nrepl-selector key binding
nrepl-switch-to-repl-buffer uses buffer matching current namespace