Start implementing version_hash
Make from_yaml backwards compatible with ruby 1.8
Merge remote-tracking branch 'origin/support_jruby_1.6.7.2' into version_hash
Merge pull request #11 from jcosmo/support_jruby_1.6.7.2

Make from_yaml backwards compatible with ruby 1.8
Move hash calculation code into Runtime
Implement hashing and add tests.
Minor reformatting
Add a test for database_definition.version_hash
Remove debug prints
Slight improvement to hash file collection test
Merge pull request #12 from jcosmo/version_hash

Version hash
Remove not very useful comments
Ensure hash is not recreated on every request