config: Allow ConfBridge DTMF menus to have '#' as the first digit.

ConfBridge allows custom DTMF menus to be created in the confbridge.conf
file by assigning a DTMF key sequence to a sequence of actions as follows:

DTMF-sequence = action,action...

Unfortunately, the normal config file processing code interprets an
initial '#' character as starting a directive such as #include.

* Add the ability to escape the first non-blank character in a config line
so the '#' character can be used without triggering the directive
processing code.

(closes issue AFS-2)
(closes issue ASTERISK-22478)
Reported by: Nicolas Tanski
Patches:
      jira_asterisk_22478_v11.patch (license #5621) patch uploaded by rmudgett (modified)

Review: https://reviewboard.asterisk.org/r/2969/
........

Merged revisions 402407 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@402416 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/confbridge/conf_config_parser.c

@@ -426,6 +426,13 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 					each channel using the application.  Like the User and Bridge profiles a menu
 					is passed in to ConfBridge as an argument in the dialplan.</para>
 					<para>Below is a list of menu actions that can be assigned to a DTMF sequence.</para>
+					<note><para>
+						To have the first DTMF digit in a sequence be the '#' character, you need to
+						escape it.  If it is not escaped then normal config file processing will
+						think it is a directive like #include.  For example: The mute setting is
+						toggled when <literal>#1</literal> is pressed.</para>
+						<para><literal>\#1=toggle_mute</literal></para>
+					</note>
 					<note><para>
 					A single DTMF sequence can have multiple actions associated with it. This is
 					accomplished by stringing the actions together and using a <literal>,</literal> as the
@@ -450,7 +457,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 						<enum name="toggle_mute"><para>
 							Toggle turning on and off mute.  Mute will make the user silent
 							to everyone else, but the user will still be able to listen in.
-							continue to collect the dtmf sequence.</para></enum>
+							</para></enum>
 						<enum name="no_op"><para>
 							This action does nothing (No Operation). Its only real purpose exists for
 							being able to reserve a sequence in the config as a menu exit sequence.</para></enum>