opensips: replaced `usrloc_memory` with `usrloc_flags`.

`usrloc_memory` didn't compile properly.
opensips: default `max_contacts` to 0.

Using a non-zero value drives CouchDB crazy.
Update changelog for 0.0.165 release
Update changelog for 0.0.165 release
opensips: applied `usrloc_flags` changes everywhere
opensips: Enforce min-expires with 423 responses.
Update changelog for 0.0.166 release