avpops: create a local pv structure when parameter is only flags

- flags details are stored inside it
- fixes crash at startup reported by Kevin Scott Adams, FS#381

(cherry picked from commit 3c88f1de9d647db8a14bae45af1fa3b34f74d4e6)
tm: reset temporary linking of reply to transaction after branch failure route execution

- reported by Robert Boisvert, FS#379

(cherry picked from commit 0ebc983a422cd5ee4baa39bb3ef3bdbeeefd4571)
snmpstats: fixe MIB file definitions

- patch by takeshi, FS#363

(cherry picked from commit ab75785aa707f10fdbccfb0531a0f35e820f5ebc)
db_flatstore: update timestamp for kamailio specific rpc rotate

- do also in 'rotate' command, not only in 'k_rotate'
- from a patch by Abdelkader Allam

(cherry picked from commit b15aefa31e45f1ad6a45b64905f9fae24e0f790e)
modules/pv: fixed params and param transformation

- params need to be taken from sip_params field of sip_uri struct
(cherry picked from commit e54b3ec673cb32664a1e8de2e591190f22216724)
modules/pua: added some missing lock releases
(cherry picked from commit 4eb338611e716e7a32f252acbae52bace6047a0a)