If FS is not behind NAT, then every call generates at least three
INFO-level log messages:

  [INFO] switch_nat.c:589 NAT port mapping disabled

This is useless noise.  The message is only interesting if you do have
NAT enabled but mapping disabled, which might indicate a configuration
issue.

With this change, we just skip the entire nat_add_mapping function if
the NAT system isn't initialized or we're not behind NAT.

FS-5913 --resolve

Putting `net-snmp-config --cflags` into CFLAGS causes major pollution;
it overrides optimization and debugging levels, warnings, and more.
While normally we do want to automatically locate library headers,
there has to be a better way to do this.  libsnmp is normally in the
usual place and doesn't need special handling.  Perhaps people with
libsnmp in a weird place should just need to add the -I flag to their
CFLAGS before build.

Calling out to net-snmp-config --agent-libs causes transitive
dependencies to get pulled in, but we don't need those -- a sensible
dynamic linker pulls those in automatically.  Trying to track the
transitive dependencies manually would be a losing battle.

People were recently hitting this on Debian sid/jessie, where libpci
is in the transitive dependency list but isn't otherwise one of our
build dependencies.

CID: 1211948 fix memory leak of decoded iks message in function parse_plain_auth_message in mod_rayo

FS-6506 --resolve Technically when you are not using groups you do not add a <users> tag inside <domain> you just put several <user> tags in <domain> This patch will consume an extraneous <users> tag and move on making it work either way.

sofia is treating all notify sending as if they were natted rather than when nat is detected.  This causes issues on some polycoms that use strange ports in their contact for getting notifies that do not match the port the calls come from

Correction to commit 0ba59aa6 using the correct variable in tel uri param parsing for mod_sofia

FS-4779 FS-6467 the behaviour from 4479 is now masked behind the param 3pcc-reinvite-bridged-on-ack FS-6467 please test master

This seems to be a paradox when running a perl script from a session then executing perl again on the same session from a different thread.
I fixed it by converting any execution of perl in the execute_on_* family of operators to only run background mode which is to store the command in the session stack to be executed only by the session thread instead of on the spot by the outide thread.  changing the execute_on_answer to perl::/path/to/script.pl would also eliminate the crash in code that has not been updated with this patch.

This is just a limitation of embedded perl we have to live with.

Expanding on 05263818 to support boolean tel url params in mod_sofia

Conflicts:
	src/mod/applications/mod_conference/mod_conference.c

We were calling switch_epoch_time_now() twice for no good reason.

This allows building mod_soundtouch in clang as clang doesn't support
gcc's -fcheck-new.

These haven't been touched in years; they can't possibly still be
applicable.