ENH: Change default low and high attribute of LargeRangeSliderEditor from 0, 1 to undefined.

Currently the LargeRangeSliderEditor has 0 and 1 as default value for the low and high attribute, respectively.
I find that strange since the editor is meant for large ranges. I would suggest to change it to the same default values as the other RangeEditors (SimpleSliderEditor, RangeTextEditor, SimpleSpinEditor and LogRangeEditor) have, ie. undefined or None, so that
the limits are from -infinite to +infinite. Then it will be simpler to construct a one sided LargeRangeSliderEditor because you then only have to specify the one sided limit.