Replace '+' (the plus sign) with international dialing code

I have tested this in FreePbx 2.4:

first pass the + in the outbound route by adding
+Z.

then add in the trunk's dial rule like this
+|011+Z. (if trunk in N. America)
+|0011+Z. (if trunk in AU)
+|00+Z. (if trunk in EU/CN etc.)
etc...

Now you can dial +1234567890x from any softphone,
and let trixbox convert to the right international dialing code.