* dotfiles/bash_config.sh:

  - purge is now a function that removes emacs temporary files, .pyc
    files, and .elc files.

  - adding a realpath function to work with absolute paths

  - adding a prepend_to_path function to prevent including duplicates
    or bogus entries in PATH

  - removing references to my home's absolute path

Tested-by: Nicolas Couture <nicolas.couture@gmail.com>