add 'systemname' option to prefix channel unique IDs with (issue #5825)

convert chan->uniqueid to a stringfield from a fixed-size buffer


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@10088 65c4cc65-6c06-0410-ace0-fbb531ad65f3

doc/asterisk-conf.txt

@@ -62,6 +62,7 @@ maxload = 1.0					; The maximum load average we accept calls for
 maxcalls = 255					; The maximum number of concurrent calls you want to allow 
 execincludes = yes | no 			; Allow #exec entries in configuration files
 dontwarn = yes | no				; Don't over-inform the Asterisk sysadm, he's a guru
+systemname = <a_string>				; System name. Used to prefix CDR uniqueid and to fill ${SYSTEMNAME}
 
 [files]
 ; Changing the following lines may compromise your security

doc/channelvariables.txt

@@ -594,6 +594,7 @@ ${TIMESTAMP}	 	* Current date time in the format: YYYYMMDD-HHMMSS (Deprecated; u
 ${TRANSFER_CONTEXT} 	Context for transferred calls
 ${FORWARD_CONTEXT}     Context for forwarded calls
 ${UNIQUEID}	 	* Current call unique identifier
+${SYSTEMNAME}		* value of the systemname option of asterisk.conf
 
 Application return values
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