Collecting nested use rules

[dakochik]

File boo.smk:

if condition:
  use rule r as rule_new1
else:
  use rule r as rule_new2

File foo.smk:

module M:
   snakefile: "boo.smk"

use rule * from M as other_*

use rule other_rule_new1 as bb with: # Unresolved reference
   threads: 2

other_rule_new1 won't be resolved, but it should

Related to #413