Improved support for working with remote JVMs via tramp

Remote nREPL servers will ask Emacs to load Clojure files (and jar libraries) using paths that are local to the remote machine, but may not resolve when loaded on the local machine. In practise, this means that nrepl jumps often don't work and create empty buffers, confusing the user.

This commit detects the use of tramp when the nrepl connection is initiated. Subsequent instructions to load remote files and resolved via the same tramp properties. This should not affect users developing against a local nrepl instance, but greatly improves the experience of those developing or debugging a remote nrepl instance.