lib/bitString.js
function pad (n, width, z) {
  if (typeof n !== 'string') throw new Error('bitString#pad: Need String');
  z = z || '0';
  while(n.length < width) {
    n = z + n;
  }
  return n;
}
function pad (n, width, z) {
  if (typeof n !== 'string') throw new Error('bitString#pad: Need String');
  z = z || '0';
  while(n.length < width) {
    n = z + n;
  }
  return n;
}
function pad ( n , width , z ) { if ( typeof n !== 'string' ) throw new Error ( 'bitString#pad: Need String' ) ; z = z || '0' ; while ( n . length < width ) { n = z + n ; } return n ; }
Pad a string to atleast desired width
@param  {string} n      String to pad
@param  {integer} width Width to pad to
@param  {char=} z       Optional pad char, defaults to '0'
@return {string}        Padded string
Pad a string to atleast desired width