Update contrib script live_ast to invoke Asterisk with valgrind and suppression file.

Update contrib script live_ast to invoke Asterisk with valgrind and suppression file.

* Added valgrind_compare script to compare two valgrind log files for
differences.

(issue ASTERISK-17339)
Reported by: Tzafrir Cohen
Patches:
      valgrind_compare (license #5035) script uploaded by Tzafrir Cohen
      live_ast_valgrind.diff (license #5035) patch uploaded by Tzafrir Cohen
      live_ast_valgrind_v2.diff (license #5185) patch uploaded by Paul Belanger

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@350127 65c4cc65-6c06-0410-ace0-fbb531ad65f3