Fix compiling with LOW_MEMORY.

Modified handle_verbose to be LOW_MEMORY aware, removed old RTP related code
in chan_sip.

(closes issue #16381)
Reported by: michael_iedema
Patches: 
      ast_complete_source_filename.patch uploaded by michael iedema (license 942)
      modified by me


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@236893 65c4cc65-6c06-0410-ace0-fbb531ad65f3