biodevc

I just saw that @michaelbeaumont had done the groundwork for function privs so copied and tweaked his query. It should address #djrobstep/migra#64

> I implemented the schema privileges. @biodevc could you pickup [stack11@2107f08](https://github.com/stack11/schemainspect/commit/2107f082613def968615dc0e48413b9555193056) in your PR? Just added your mods but altered the query since it was producing wierd results for me

> Huh what results? We've been using this patch in production and it always worked for us. If a role has 'group' members and that role has priveleges granted to...

> @biodevc could you rebase? I've given up hope of this pull request ever going anywhere. Migra appears to be a dead project at this stage.