Added new channel command FTDM_COMMAND_SET_POLARITY
         ftmod_wanpipe - Added support to enqueue polarity events on FXO lines
	 ftmod_wanpipe - Added support to set polarity on FXS lines
	 ftmod_analog - Added support to answer and hangup FXO lines on polarity reverse
	 ftmod_analog - Added support to reverse polarity in the FXS line on answer and hangup
	 mod_freetdm - Added parameters answer-on-polarity, hangup-on-polarity and polarity-delay
                       to enable those analog features

         ftmod_r2 - updated api help and removed references to threads per channel,
                    not used anymore

mod_conference: Add XML output for conference run time, recording status and member mute-detect. Also add events for recording start and stop.

This work was funded by Xpander Communications.

	* Replace ftdm_channel_flag_t with defines. We reached the 32bit limit where does not seem reliable
          to keep using enum.
	* Flags member for ftdm_channel_t is now uint64_t
	* Added FTDM_CHANNEL_CALL_STARTED flag to indicate when the API user knows about a call
	* Refactored raw_data member for ftdm_sigmsg_t. If raw_data needs to be freed it must be requested explicitly
          through the autofree member
	* Added collected member to ftdm_sigmsg_t for FTDM_SIGEVENT_COLLECTED data instead of using raw_data
	* Created define FTDM_DIGITS_LIMIT for DNIS/ANI digits limit
	* Fix some stat checks and outdated code in ftmod_analog
	* Refactored ftdm_channel_get_history_str API to return the time offsets and time since last state change
	* Do not send FTDM_SIGEVENT_STOP and FTDM_SIGEVENT_RELEASED on calls that were never reported to the user

The raw_data member is used for passing heap allocated data with an event,
(e.g. strings of dtmf data) the memory is freed after the event has been processed.

Recent changes in the event structure added a way to pass sig status changes inline,
so remove the raw_data usage for FTDM_SIGEVENT_SIGSTATUS_CHANGED events.

NOTE: This (finally) fixes a bug in ftmod_libpri that was caused by
      the event handling changes (stack corruption due to using free()
      on a variable on the stack, which turned into a NULL ptr deref
      caused by some compat code in ftdm_io.c:ftdm_span_send_signal().

Compiles and tested on my BRI setup, i did a quick audit of all
places that generate FTDM_SIGEVENT_SIGSTATUS_CHANGED events and
except for the sangoma_boost module there's nothing else that left
using raw_data for this event.
Signed-off-by: Stefan Knoblich <s.knoblich@axsentis.de>

freetdm: ftmod_libpri - update to use proper structure member for signaling status change notifications

freetdm: add __USE_BSD to ftdm_os, needed by unistd.h for usleep() and string.h to define strcasecmp()
	 add -Werror even when the compiler is unknown. This is just a work-around to gcc not being detected
	 as GNU by our current standalone build (not bootstrapped through FreeSWITCH)

Signed-off-by: Stefan Knoblich <s.knoblich@axsentis.de>