* Command no longer need to be run from the base directory of the repo.
* blackbox_edit now asks "are you sure?" and is greatly simplified.
_blackbox_common.sh:
* add_filename_to_cryptlist now accepts paths relative to cwd.
* fail_if_not_on_cryptlist now accepts paths relative to cwd.
* new function: vcs_relative_path reports a path to the file relative to the REPOBASE.
* new function: is_on_cryptlist
plus...
* Some minor performance enhancesments and cleanups.
* confidence_test.sh now tests some commands while not in REPOBASE.
