[update] assert that follow dependency is calculated only once

Signed-off-by: Shahbaz Youssefi <ShabbyX@gmail.com>
[update] more stuff similar to ef6cbc7

Signed-off-by: Shahbaz Youssefi <ShabbyX@gmail.com>
[update] convert follow remove cycle

Now uses a proper strongly connected components algorithm.

Signed-off-by: Shahbaz Youssefi <ShabbyX@gmail.com>