matplotlib Code

ipython integration.

force draw if in interactive mode (so draw() does not need to
be explicitly invoked if running in ipython)

minor rec2excel enhancements

Remove dead code.

Prevent mathtext cache from getting out of hand.

Avoid matching widths and heights too often.

Make things more robust to changes in dpi.

Make autolayout a configuration option.

simplify time/date handling

updated autofmt_xdate to work in more cases. it no longer raises if axes aren't subplots