Expand cel_custom.conf.sample.

Include the usage of CSV_QUOTE() to ensure data has valid CSV formatting.  Also list
the special CEL variables that are available for use in the mapping.


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@283173 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configs/cel_custom.conf.sample

@@ -17,5 +17,15 @@
 ; in the cel-custom directory under your Asterisk logs directory.
 ;
 
+;
+; Within a mapping, use the CALLERID() and CHANNEL() functions to retrieve
+; details from the CEL event.  There are also a few variables created by this
+; module that can be used in a mapping:
+;
+;    eventtype  - The name of the CEL event.
+;    eventtime  - The timestamp of the CEL event.
+;    eventextra - Extra data included with this CEL event, typically along with
+;                 an event of type USER_DEFINED from CELGenUserEvent().
+;
 [mappings]
-;Master.csv => "${eventtype}","${eventtime}","${CALLERID(name)}","${CALLERID(num)}","${CALLERID(ANI)}","${CALLERID(RDNIS)}","${CALLERID(DNID)}","${CHANNEL(exten)}","${CHANNEL(context)}","${CHANNEL(channame)}","${CHANNEL(appname)}","${CHANNEL(appdata)}","${CHANNEL(amaflags)}","${CHANNEL(accountcode)}","${CHANNEL(uniqueid)}","${CHANNEL(linkedid)}","${CHANNEL(peer)}","${CHANNEL(userfield)}"
+;Master.csv => "${CSV_QUOTE(${eventtype})}","${CSV_QUOTE(${eventtime})}","${CSV_QUOTE(${CALLERID(name)})}","${CSV_QUOTE(${CALLERID(num)})}","${CSV_QUOTE(${CALLERID(ANI)})}","${CSV_QUOTE(${CALLERID(RDNIS)})}","${CSV_QUOTE(${CALLERID(DNID)})}","${CSV_QUOTE(${CHANNEL(exten)})}","${CSV_QUOTE(${CHANNEL(context)})}","${CSV_QUOTE(${CHANNEL(channame)})}","${CSV_QUOTE(${CHANNEL(appname)})}","${CSV_QUOTE(${CHANNEL(appdata)})}","${CSV_QUOTE(${CHANNEL(amaflags)})}","${CSV_QUOTE(${CHANNEL(accountcode)})}","${CSV_QUOTE(${CHANNEL(uniqueid)})}","${CSV_QUOTE(${CHANNEL(linkedid)})}","${CSV_QUOTE(${CHANNEL(peer)})}","${CSV_QUOTE(${CHANNEL(userfield)})}"