Merging Fernando's trunk (fp-trunk-dev) and Brian's edits (fp-review). This is a huge merge of months worth of work by Fernando and Brian. Some highlights: * The test suite has been ported to use the new APIs. * The test suite runs and passes on all platforms!!! * The IPython Sphinx directive has been updated to use the new APIs. * %history works again. * New %tb magic for showing last traceback. * Significant design improvements in the config loaders and applications. * Zillions of bugs fixed. * Completely new %pylab implementation that uses the new GUI support. This allows pylab to be enabled *at runtime*. * Many other things.