Revert "--interactive option for 'run' verb"

This reverts commit e6f247aa1ffa88eabeb2a5b6c8d13c91af46eaec.
Revert "Some refactoring for more efficient and consistent checking of recipe validity"

Reverting this just before releasing 0.3.1.

This reverts commit 042b828f372778158076424247ef7ecb2e1acd51.