Assert parse of sub select with join.
Scanner now finds `AND` in join and sub-select.

See #46.
Test that compiler can format `FROM ON AND` SQL.

See #46.
Honor `AND` in sub-select.

Closes #46.
Test nested sub-query scanning.

See #49.
Fix sub-select `AND` compiler test count.
Use Cadence to implement `Relatable.select`.
Make `compiler.compile` to synchronous.

There was no need for it to accept a callback.
Remove callback from `compileSelect`.
Remove all callbacks from `compile` internals.
Test nested sub-query compilation.

It just wants to work.

See #49.
Test nested sub-selects.

Closes #49.
Merge branch `nested` into `master`.