Added unit tests for the data buffer API. These tests include creating a
data buffer, putting payloads into the buffer, resizing the buffer, and
the nominal case for data buffer usage, which consists of adding
the max number of payloads to the buffer, checking to see if the correct
payloads are present, then adding more payloads and checking again to
see if the previous payloads were replaced or not.

For more information, refer to the wiki page:
https://wiki.asterisk.org/wiki/display/AST/WebRTC+User+Experience+Improvements

Change-Id: Id5b599aa15a5e61d0ec080f97cd0c57bd07e6f8f

Adds a data buffer with a configurable size that can store different
kinds of packets (like RTP packets for retransmission). Given a number
it will store a data packet at that position relative to the others.
Given a number it will retrieve the given data packet if it is present.
This is purposely a storage of arbitrary things so it can be used not
just for RTP packets but also Asterisk frames in the future if needed.
The API does not internally use a lock, so it will be up to the user of
the API to properly protect the data buffer.

For more information, refer to the wiki page:
https://wiki.asterisk.org/wiki/display/AST/WebRTC+User+Experience+Improvements

Change-Id: Iff13c5d4795d52356959fe2a57360cd57dfade07

Something is causing a python2/python3 mismatch on Fedora27.

PYTHON='/usr/bin/python2'
PYTHONDEV_CFLAGS='-I/usr/include/python3.6m '
PYTHONDEV_INCLUDE='-I/usr/include/python3.6m '
PYTHONDEV_LIB='-lpython3.6m '
PYTHONDEV_LIBS='-lpython3.6m '

This reverts commit be0e9920.

Change-Id: I86dd102eb3ead199fe89178cdbadb36b4e2cfd1b

This creates 4 reserved pointers in case we need additional dependency
management fields.

Change-Id: If991ec99b779df1b2dfbd38ce1a0cd79f9e01821

This patch clears the talking flag from the channel (if already set), and
notifies listeners when that channel is put on hold. Note however, if the
endpoint continues to send audio frames and these are received by the bridge
then that channel will be put back into a "talking" state even though they
are on hold.

ASTERISK-27755 #close

Change-Id: I930e16c4662810f9f02043d69062f88173c5e2ef

AST_EXT_LIB_CHECK has several optional parameters. When an optional parameter
is left empty, [] is used to indicate this. However, this is done in the script
./configure only then, when a further parameter is not empty. For example, when
no extra libraries are needed to test the checked library, parameter 5 is not
mentioned. Except parameter 6 and higher are used, then parameter 5 must be
empty.

However, this general rule was broken
* four times for parameter 5 (extra libs) and
* three times for parameter 4 (header)
as found via the Regular Expression \[\]\). In case of parameter 5, all cases
were changed, because that happened for no reason. In case of parameter 4, an
[] improves readability actually. Therefore for parameter 4, the only case which
did not do it was changed. All this aims to create more consistency: Only do
something different if there is a reason to do so.

Change-Id: I037ef170cf1ad94497151a9ea5071a31c656cafe

The functions behind the flag and the flag itself were removed
from Asterisk 12 as incompatible with the new architecture.

Change-Id: I058493ef7a53ee290fd225bbcbb07bf46b623ccf

Remove symbols that are depreacated and replaced:
* ast_channel_datastore_alloc
* ast_channel_datastore_free
* ast_channel_cmpwhentohangup
* ast_channel_setwhentohangup
* config_text_file_save
* devstate2str
* ast_device_state_changed
* ast_device_state_changed_literal
* ast_verbose_get_by_module

Remove unused symbols:
* channelreloadreason2txt (last used in Asterisk 12).

Remove unused ast_options flags:
* AST_OPT_FLAG_END_CDR_BEFORE_H_EXTEN / ast_opt_end_cdr_before_h_exten
* AST_OPT_FLAG_VERBOSE_MODULE / ast_opt_verb_module
* AST_OPT_FLAG_INITIATED_SECONDS

Change-Id: I841255995d195f8efc1ed47af9c7a2f131c08645

* dahdi_chan_name
* dahdi_chan_name_len
* dahdi_chan_mode
* __manager_event
* dialed_interface_info

Added comment about __progname and environ being needed for FreeBSD to
prevent accidental removal in the future.

Change-Id: I3ae026bc541cd9cb572be2ffa95fc359547642b5

Change-Id: I317a82de976bbdbfe4352c243e32a7bb8f66c377

Change-Id: I140e1137906bbfcdb61c0c6304159be459ad873e

If the two formats on a channel are equal, we don't transcode and since
the generic plc needs slin to work, it doesn't get invoked.

* A new configuration option "genericplc_on_equal_codecs" was added
  to the "plc" section of codecs.conf to allow generic packet loss
  concealment even if no transcoding was originally needed.
  Transcoding via SLIN is forced in this case.

ASTERISK-27743

Change-Id: I0577026a179dea34232e63123254b4e0508378f4

Change-Id: I658141c6ec490a3e866b02d2afea757928ceaabf

Change-Id: I5133ff2ba4e030f9733fb3d050c863d72a22ae6b