FS-7654 regression on eavesdropping on channels playing a file because of channel count of 0 on write frame from stream_file

added xml fetch for channels to externally support nightmare transfer
depends on channel-xml-fetch-on-nightmare-transfer profile param (default is disabled)

FS-7597: [mod_codec2] Fixed encoded_data_len for MODE 2400, it should be 6 bytes. Also replaced 2550 bps bitrate (obsoleted operation mode) by 2400

FS-7650: #resolve [mod_verto] Fix crash when making a call from a verto user with profile-variables in their user profile

Ephemeral ECDH (ECDHE) was supported already. This patch adds Ephemeral
DH (DHE). To enable it, add DH parameters into the private-key file of
your server (agent.pem). For example via:
openssl dhparam -out dh.pem 2048

FS-7561 #resolve

The correct incantations to enable certification common name / subject
alternative name verification, per our code, are `subjects_all`,
`subjects_in`, and `subjects_out` in a Sofia profile's
`tls-verify-policy`.  What we've had in our examples and documentation
for years are `all_subjects`, `in_subjects`, and `out_subjects`.

The result of this is that we've almost certainly confused people into
using the incorrect forms.  Those poor people will believe that they
are verifying the CN/SAN of the received host certificate against the
list in `tls-verify-in-subjects` when in fact they are not.

One clear issue in this case was that the incorrect forms failed to
have any effect without providing any warning or error.  This issue
could not have persisted if we had made more noise about incorrect
input.

Given how long this has been broken, it's tempting to alias the
incorrect forms to the correct ones.  However this would certainly
break many existing installations that have, because of this error,
never actually tested their setup with CN/SAN validation enabled.

In this commit, we fix the examples and documentation, and add an
error-level log output when unknown values are passed to
`tls-verify-policy`.

Thanks-to: Andrew Patrikalakis <anrp+freeswitch@anrp.net>

FS-7720 improve play_and_detect_speech to set current_application_response channel variable as follows:

    "USAGE ERROR": bad application arguments
    "GRAMMAR ERROR": speech recognizer failed to load grammar
    "ASR INIT ERROR": speech recognizer failed to allocate a session
    "ERROR": any other errors

  This is useful for determining that play_and_detect_speech failed because the recognizer is out of licenses
  giving the developer a chance to fall back to traditional DTMF menu navigation.

Conflicts:
	src/switch_core_io.c
	src/switch_ivr_async.c