tidy up the DatabaseStep and add in full form validation support along with the ability to use the setup api to validate the connection details of possible new database creation.

new setup process working end-to-end in React now.  still more to do, but all the pieces are in place now.

update /setup/ route handling so that we only send people to setup when it's appropriate, otherwise to prevent them from accessing it.

make variable injection a function because it needs to be realized at runtime.  also add the setup token to the bootstrap info.

Revisions via new events system

update revision api tests so that they are focused on testing the endpoint functionality and not a bunch of other stuff.

flush out the unit tests for `(process-revision-event ...)` function which handles new events related to revision tracking.

rename to index to keep jekyll from barfing

Break up docs

fix placeholder on metadata field

handle subject to deal with sql backed cards

fixes #577

update readme to our current lack of a token on installation