pv: Don't log warnings when a string flag id is used

check_flag is logging a warning when the numeric id is also used via a string
alias. Don't call this function if the flag id is a string.
tm: Fix setting flags for record-route headers

The flags where set in add_uac() by counting the number of record-route
headers added by prepare_new_uac(). The latter function backups and
restores the list of lumps, so add_uac() only sees the original list,
which is not what has happened on the branch being handled.

Moving setting the flags into prepare_new_uac() fixes this.

This fixed the dialog module, which has to remove the correct number
of RR headers from the callee's routeset (which it does based on the
tm flags).
kcore: print_rr_body: return number of printed Record-Route bodies

Act like the documentation, return the number of printed RR bodies, not the
total number of RR bodies.
core: sip_msg_shm_clone: clone parsed maxforwards value in shm

maxfwd module modified the msg buf directly instead of adding a lump. In
addition it is filling the parsed value of the header field.

Clone this field into shm so later code can at least determine if the msg
has been mangled so it can retreive the original value of the header.
core: Document the right type for 'str*' in the RPC interface
mi_datagram: Send error response on out-of-memory
dmq: Lower the minimum ping interval to 5 sec

There is no real reason to have a minimum, let alone a minimum of 60 secs.
dmq: more efficient find_dmq_node_uri

No need to build a complete dmq_node, only host and port are needed.
Can be done on the stack.
dmq: check if dmq socket exists
dmq: handle failure to build callback parameter
dmq: unlock in failure path in build_notification_body()
dmq: prevent unnecessary deep copies of string when building reply body
tm: log an error message as error, not debug
tm: remove dead code
core: time_t is unsigned, handle integer underflow correctly

When the processing of the timer code takes longer than the interval, don't
sleep for 4Gs.
core: fork_*_utimer()'s interval is in microseconds

Sync comments with code and function names
tm: backup xavps before running callbacks

regular avps were being backupped, just not xavps.
dispatcher: Ignore IPv6 addresses if IPv6 lookups are disabled.
core: Don't log errors when dns find no more records

If the proxy is listeneing on both ipv4 and ipv6, DNS attempts are done for
both A and AAAA records. If the last of these lookup fails with no records
found, don't log an error if the first lookup did already return records.
perl: check for and handle memory allocation failures