Update dev guide with commit message guidelines

Updating development.txt with a short description of a typical IPython development workflow using Bazaar.

Merging from trunk.

Removed old docs/source/changes directory that is no longer being used.

cd completer: no longer greedy. If you are using a buggy readline that inserts spaces after completions (so you need to press backspace), do import ipy_completers ipy_completers.greedy_cd_completer = True

new version of the synchronization hooks closer to the ipy_editors style

fixed ipython1->IPython in cocoa/tests/test_cocoa_frontend.py

moved frontend from ipython1-dev. Got engineservice.ThreadedEngineService running, but does nto correctly propagate errors during execute()

Updating Release.py to get ready for a 0.9 release. The release is a ways off, but I want to get us thinking towards it.

Merging in ipython-ipython1b branch. This branch was used to merge in the docs from ipython1-dev, as well as the stuff from the ipython1-sconfig branch. In addition to simply merging the docs from ipython1-dev, I have completely reorganized the docs to make the easier to read and write.