Bridge DTMF hooks: Made audio pass from the bridge while waiting for more matching digits.

* Made collecting DTMF digits for the DTMF feature hooks pass frames from
the bridge.

* Made collecting DTMF digits possible by other bridge hooks if there is a
need.

ASTERISK-24447 #close
Reported by: Richard Mudgett

Review: https://reviewboard.asterisk.org/r/4123/
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Merged revisions 427493 from http://svn.asterisk.org/svn/asterisk/branches/12
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Merged revisions 427494 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@427495 f38db490-d61c-443f-a65b-d21fe96a405b
app_agent_pool: Made agent alert interruptable by DTMF.

Made agent able to interrupt the alerting beep playback with DTMF.  Any
digit can interrupt if the call does not need to be acknowledged.  Only
the first digit of the acknowledgement can interrupt if the call needs to
be acknowledged.  The agent interrupting the alerting playback builds on
the ASTERISK-24447 patch because it knows what digit interrupted the
playback and needs to be able to pass that digit to the DTMF hook digit
collection code.

ASTERISK-24257 #close
Reported by: Steve Pitts

Review: https://reviewboard.asterisk.org/r/4123/
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Merged revisions 427508 from http://svn.asterisk.org/svn/asterisk/branches/12
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Merged revisions 427512 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@427519 f38db490-d61c-443f-a65b-d21fe96a405b