More code cleanup

1. Add prefix erl- to process- functions and variables
   Process is part of emacs so be clear and don't pollute that name
   space.

2. Remove erpc which seems to be a develment helper but isn't
   particularly better than the standard M-: (eval-expression).

3. Remove maybe-select-db-rebuild
Also add erl- prefix to display-message-or-view
Merge pull request #27 from leoliu/master

More code cleanup