This adds support for indexes to automigrate() and adds a check for the indexes existence to the migration.coffee 'should run migration' test.
All unit tests continue to pass. The code snippets for adding indexes are the declarative versions of the methods used in alterTable(), so the indexes should be consistant with previous declarations/additions.
Should resolve bug #5.
As a side node, also removed the 'UNIQUE' clause from the `id` declaration as it is redundant with the 'PRIMARY KEY' declaration so far as I'm aware and results in what seems to be a second index getting maintained for no reason. (If I'm wrong about this I'd be intrested in the explanation. MySQL does have a lot of oddities.)