(closes issue #12467)

Reported by: atis
Tested by: murf

This upgrade adds the ~~ (concatenation) string operator to expr2.
While not needed in normal runtime pbx operation, it is needed when
raw exprs are being syntax checked. This plays into future syntax-
unification plans. By permission of atis, this addition in trunk 
and the reason of why things are as they are will suffice to close
this bug.

I also added a short note about the previous addition of "sip show sched"
to the CLI in CHANGES, which I discovered I forgot in a previous commit.




git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@114423 65c4cc65-6c06-0410-ace0-fbb531ad65f3

doc/tex/ael.tex

@@ -38,7 +38,7 @@ AEL is really the merger of 4 different 'languages', or syntaxes:
       language, that AEL will compile into.
 \end{itemize}
 
-Any programmer of AEL should be familiar with it's syntax, of course,
+Any programmer of AEL should be familiar with its syntax, of course,
 as well as the Expression syntax, and the Variable syntax.
 
 
@@ -114,9 +114,9 @@ the Asterisk environment!
 
 \section{Getting Started}
 
-The AEL parser (pbx\_ael.so) is completely separate from the module
+The AEL parser (res\_ael.so) is completely separate from the module
 that parses extensions.conf (pbx\_config.so). To use AEL, the only
-thing that has to be done is the module pbx\_ael.so must be loaded by
+thing that has to be done is the module res\_ael.so must be loaded by
 Asterisk. This will be done automatically if using 'autoload=yes' in
 \path{/etc/asterisk/modules.conf}. When the module is loaded, it will look
 for 'extensions.ael' in \path{/etc/asterisk/}. extensions.conf and