update CHANGES and bump version to 0.5.1
bzlib.command.Search - fix crash on empty result
Merge branch 'master' into maint

Conflicts:
	CHANGES
bump version to 0.5.2
administrative updates to setup.py and README

* rename README to README.rst
* update a few titles is README
* change author email to frase@frase.id.au
* change url to GitHub page
* update trove classifiers