'only' and 'exclude' options for filtering models
Update dependencies, temporarily holding back Rails.
Merge pull request #29 from assembler/master

'only' and 'exclude' options for filtering models
Conservative dependency for ruby-graphviz.
Strip whitespace.
Remove more whitespace.
Allow database types that are not supported by Rails.
Fix tests for Rails 3.2.
Support for Edge Rails.
Improve CLI.
Update documentation.
Update documentation and prepare for release.
Update install page.
Ignore scales and limits that cannot be converted to an integer.
Update changelog.
Keep 1.8.7 compatibility.
Remove leftovers from Jeweler.
Add a documentation task.
Changelog is now in markdown format.
Reinstate example task.