bash_prompt is a collection of custom bash prompts to be loaded using the
provided `set_prompt` function.

Example of use, assuming that bash_prompt is under ~/.bash/:

  # load git prompt support
  [ -f /usr/lib/git-core/git-sh-prompt ] && . /usr/lib/git-core/git-sh-prompt

  # load function to set custom shell prompts
  if [ -f ~/.bash/bash_prompt/set_prompt ];
  then
    . ~/.bash/bash_prompt/set_prompt

    # set a different prompt for the root user
    if [ $UID -eq 0 ];
    then
      set_prompt fire
    else
      set_prompt iceg
    fi 
  fi

The prompts can contain backslash-escaped special characters as specified in
the bash(1) man page, or any ANSI escape sequences as described in the
console_codes(4) man page.

The `set_prompt` function defines symbolic constants for the most used escape
sequences, see the source code for the details.

Inspired by bashish: http://bashish.sourceforge.net/