Simplify search tree by canonicalizing message sets, converting NOT away from NOT (list) and dropping extra sub lists. Fix also handling NOT messagesets.
Simplify search tree by canonicalizing message sets, converting NOT away
from NOT (list) and dropping extra sub lists. Fix also handling NOT
messagesets.

Distrotech/dovecot,Distrotech/dovecot,Distrotech/dovecot,Distrotech/dovecot,Distrotech/dovecot