New doc format up

The Python 2.6 and 3.0 docs have now been moved over to the new format (although the 3.0 docs are so out of date that you should not use them as a reference)! Huge thanks goes to Georg Brandl for taking on the challenge of moving the docs from LaTeX to reStructuredText and initially writing the new doc build system, doctools. And thanks to everyone who has contributed subsequently!