Code style
[Fix #501] Nil appearing in nrepl-server buffer name when no project directory.
Merge pull request #504 from jonpither/nil-designation

[Fix #501] Nil appearing in nrepl-server buffer name when no project dir...
Adding cider-change-buffers-designation.
Merge pull request #500 from jonpither/rename-buf

Change cider buffers designation
Use cider-from-nrepl-filename-function to translate nREPL-Server
pathnames to elisp pathnames
Use cider-to-nrepl-filename-function to translate elisp pathnames to
nREPL-Server pathnames