Commits on Mar 25, 2016
  1. BUG: Validate float_format setting as callable or None

    tdhopper authored and jreback committed Mar 24, 2016
    The `float_format` setting takes either None or a callable object
    that returns a formatted string given a float value. Currently, the
    setting isn't validated, so cryptic error messages are returned
    if, for example, a format non-callable format string is given (see
    \#12704). Add a standard validation method and use it to validate
    the `float_format` setting.
    closes #12706
    closes #12711