Console fixes

This includes the fixes for progress bar resizing from #843, as well as some additional fixes I made for sane color support on Windows (currently colors are only enabled in IPython; getting ANSI color codes to work in the normal command prompt on Windows is a bit trickier and will have to wait for another time).

Also fixes color printing to work on Python 2.6, where previously it was a bit broken.  These other color printing fixes were discussed in mdboom/astropy#13, but I thought it would be best to create a new PR before considering merging it.