Merged revisions 304950 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.8

........
  r304950 | tilghman | 2011-01-31 00:41:36 -0600 (Mon, 31 Jan 2011) | 18 lines
  
  Change mutex tracking so that it only consumes memory in the core mutex object when it's actually being used.
  
  This reduces the overall size of a mutex which was 3016 bytes before this back
  down to 216 bytes (this is on 64-bit Linux with a glibc-implemented mutex).
  The exactness of the numbers here may vary slightly based upon how mutexes are
  implemented on a platform, but the long and short of it is that prior to this
  commit, chan_iax2 held down 98MB of memory on a 64-bit system for nothing more
  than a table of 32767 locks.  After this commit, the same table occupies a mere
  7MB of memory.
  
  (closes issue #18194)
   Reported by: job
   Patches: 
         20110124__issue18194.diff.txt uploaded by tilghman (license 14)
   Tested by: tilghman
   
  Review: https://reviewboard.asterisk.org/r/1066
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@304951 65c4cc65-6c06-0410-ace0-fbb531ad65f3