Include docs in sdist, so that packages can build docs.
Merge pull request #10 from tomprince/docs

Include docs in sdist, so that packages can build docs.
Add docstrings to auto-generated methods
Polish README and motto
Add simple benchmark script
A slightly better intro into examples
Fix MANIFEST.in
Be more explicit about comparing

Only instances of identical classes should be compared.
Introduce new Attribute class
Add support for default factories
Add changelog entry
Make the teaser use Attribute
Add Rich & Julian for their feedback
Two digits should be enough for everybody
Doc polishing
Add default_value too

It's about convenience after all.
Add sphinx version tags
Use the much nicer default_value for teaser
Move main attribute up
Move tutorial-ish above API docs.