Add documentation for FAX logger level.

(closes issue #17715)
Reported by: vrban
Patches:
      17715.patch uploaded by pabelanger (license 224)
Tested by: vrban


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@279566 65c4cc65-6c06-0410-ace0-fbb531ad65f3

CHANGES

@@ -484,6 +484,8 @@ Fax
  * A spandsp based fax backend (res_fax_spandsp) has been added.
  * The app_fax module has been deprecated in favor of the res_fax module and
    the new res_fax_spandsp backend.
+ * A new FAX logger level has been created for spandsp replacing the DEBUG logger
+   level. The logger.conf.sample file has been update to include an example. 
 
 Miscellaneous
 -------------

UPGRADE.txt

@@ -106,6 +106,9 @@ From 1.6.2 to 1.8:
   482 Loop Detected response. The dialplan will just continue from where it
   left off.
 
+* All fax-related messages from spandsp, that previously went to DEBUG logger
+  level, will now be logged to a FAX logger if possible.
+
 From 1.6.1 to 1.6.2:
 
 * SIP no longer sends the 183 progress message for early media by

configs/logger.conf.sample

@@ -75,6 +75,7 @@
 ;    error
 ;    verbose
 ;    dtmf
+;    fax
 ;
 ; Special filename "console" represents the system console
 ;
@@ -106,7 +107,7 @@
 console => notice,warning,error
 ;console => notice,warning,error,debug
 messages => notice,warning,error
-;full => notice,warning,error,debug,verbose
+;full => notice,warning,error,debug,verbose,dtmf,fax
 
 ;syslog keyword : This special keyword logs to syslog facility
 ;