Pass opts[:schema] through to jdbc getTables method
Minor tweak for jdbc Database#tables commit, and update CHANGELOG

:schema should be allowed to be specified as a symbol, as it is
on other adapters.
Make SQLTime#to_s return a string in HH:MM:SS format, since it shouldn't include date information
Add example for a `rake db:migrate` task.
Merge branch 'rake-migrate-docs' of git://github.com/avdi/sequel