Changes 3.6.7:
* Reorganize the Unix interface in os_unix.c
* Added support for "Proxy Locking" on MacOSX.
* Changed the prototype of the sqlite3_auto_extension() interface in a way
  that is backwards compatible but which might cause warnings in new
  builds of applications that use that interface.
* Changed the signature of the xDlSym method of the sqlite3_vfs object in
  a way that is backwards compatible but which might cause compiler
  warnings.
* Added superfluous casts and variable initializations in order to
  suppress nuisance compiler warnings.
* Fixes for various minor bugs.

(adam)