Merge pull request #560 from bjori/PHP-soup-cleanup

Spring cleaning

* bjori/PHP-soup-cleanup:
  More unused stuff
  Lift MAKE_COPY_ZVAL from php-src rather then use our homebrewed version
  More unused weirdness
  Remove dead code
  Remove unused struct
  Remove cursor tracking leftovers since 1.2
  Kill the Cursor right away, rather then going down complex checks
  Got no idea where this came from, but its not used
  We don't do threading: Killing unused code
  Remove unused flag (MONGO_CURSOR) and multi-declaration of mongo_cursor_free_le
  Remove unused stuff
Fix build on 5.3.6 an earlier