function jscoverage_getBooleanValue(s) {
  s = s.toLowerCase();
  if (s === 'false' || s === 'f' || s === 'no' || s === 'n' || s === 'off' || s === '0') {
    return false;
  }
  return true;
}
Returns the boolean value of a string.  Values 'false', 'f', 'no', 'n', 'off',
and '0' (upper or lower case) are false.
@param  s  the string
@return  a boolean value