Allows find operations to define restrictions on what models to get based on the 'contain' parameter, including ability to override binding settings on the fly. Go through the test cases to get a crash course about some of the available functionality.
git-svn-id: https://svn.cakephp.org/repo/branches/1.2.x.x@6918 3807eeeb-6ff5-0310-8944-8be069107fe0
