Cleans up interface (it's now a command line option) and renames project to "sqlcache" in the all-one-word style. Still has issues to do with concurrency, retrying transactions, and foreign function calls that either rely on state or have side effects.

fun f [r] [[Id, Foo] ~ r] (x : $(map (fn ts => $ts) r ++ [Id = int, Foo = string]))
    : $(map (fn ts => $ts) r ++ [Foo = string]) = x

val r = {}
val x : $(map (fn ts => $ts) _ ++ [Foo = string]) = f r