In an earlier release, inbound registrations on a reliable transport
were pruned on Asterisk restart since the TCP connection would have
been torn down and become unusable when Asterisk stopped.  This same
process is now also applied to inbound subscriptions.

Also fixed issues in res_pjsip_registrar where it wasn't handling the
monitoring correctly when multiple registrations came in over the same
transport.

To accomplish this, the pjsip_transport_event feature needed to
be refactored to allow multiple monitors (multiple subcriptions or
registrations from the same endpoint) to exist on the same transport.
Since this changed the API, any external modules that may have used the
transport monitor feature (highly unlikey) will need to be changed.

ASTERISK-27612
Reported by: Ross Beer

Change-Id: Iee87cf4eb9b7b2b93d5739a72af52d6ca8fbbe36

res_pjsip_registrar_expire remains as an empty module for now.

Change-Id: Ib93698938bae548d2199cb542f3692d1a171239f

Because of a copy-and-paste from the script build_tools/download_externals,
the script build_tools/list_valid_installed_externals got its local variables.
However in the latter, three variables were not used actually.

Change-Id: I252de5a98c17ea54459174875357c22c2eebe8d5

The previous fix broke the case
HAVE_SYSINFO = no
HAVE_SYSCTL = yes
HAVE_SWAPCTL = no
which occurs on FreeBSD 11.1 for example.

ASTERISK-26563

Change-Id: If77c39bc75f0b83a6c8a24ecb2fa69be8846160a

clang 4.0 warned about this.

ASTERISK-27630

Change-Id: Ie2725048c661c1792d8b1d498575144350b6e9ba

Because of a copy-and-paste error, the Asterisk project was using __typeof
instead of typeof. It works because typeof, __typeof, and __typeof__ are
supported by GCC, but here the escaped variant was not intended. Therefore,
for consistence, we change this to typeof.

Change-Id: I2a962c3e596e882f691a19345445b14571a5f07c

ASTERISK-16172

Change-Id: I2fb564258cd4db0f35952ad48b8687355c2dcad3

ASTERISK-27603

Change-Id: I65c587534c0ae364f063d68da1bed40bb3d5e8aa

Move initialization of units which do not require configuration to occur
before preload modules.  This leaves only units which load config between
module preload and regular load stages.

Change-Id: I1d15384acad16a22c3498124421af474fa517478

The code which handled loading modules had too many situations which
would result in halting Asterisk startup.  Treat most errors as declines
instead of failures.  The exception is when the module load function
returns AST_MODULE_LOAD_FAILURE or an invalid code.

Clear the missingdeps vector when appropriate to ensure the next loop
starts clean.

ASTERISK-27620

Change-Id: I45547d9641fd45bd86d80250224417625631ad84

This removes references that are no longer needed due to automatic
references created by module dependencies.

In addition this removes most calls to ast_module_check as they were
checking modules which are listed as dependencies.

Change-Id: I332a6e8383d4c72c8e89d988a184ab8320c4872e

ASTERISK-27581

Change-Id: If6af275764741a11030f0a4fd324fa29b376d74e

Add an AMI action which provides information on all
configured Contacts.

ASTERISK-27581

Change-Id: I2eed42c74bbc725fad26b8b33b1a5b3161950c73

I've audited all modules that include any header which includes
asterisk/optional_api.h.  All modules which use OPTIONAL_API now declare
those dependencies in AST_MODULE_INFO using requires or optional_modules
as appropriate.

In addition ARI dependency declarations have been reworked.  Instead of
declaring additional required modules in res/ari/resource_*.c we now add
them to an optional array "requiresModules" in api-docs for each module.
This allows the AST_MODULE_INFO dependencies to include those missing
modules.

Change-Id: Ia0c70571f5566784f63605e78e1ceccb4f79c606

ASTERISK-27607

Change-Id: I23d00ded955c4afd5f2c3c9dc96dcb48b3f74eec

The installation script and the new configure option --with-pjproject-bundled
aimed to accomplish the same. However, the installation script was out of
date. Users should go for the maintained configure option, or the Wiki.

ASTERISK-24598

Change-Id: Icbf4b562f81f7c05bd24a3805bd46c0beb4ebd44