Allow directive settings to use configs

[spookydonut]

/mob/proc/foo()
    set SpacemanDMM_should_call_parent = TRUE
/mob/living/foo()
    set SpacemanDMM_should_call_parent = FALSE

[procdirective]

[procdirective.must_call_parent]
can_be_disabled = false

============================================================
Gathering proc settings...

test.dm, line 4, column 5:
warning: /mob/living/proc/foo sets SpacemanDMM_should_call_parent false, but it cannot be disabled.

============================================================
Analyzing proc bodies...

test.dm, line 3, column 16:
error: proc never calls parent, required by /mob/proc/foo
- 2:5: required by this must_call_parent annotation

Procs analyzed: 2. Errored: 0. Builtins: 324.

i dont know how to do this in a non-ass way yet