Revision 1328481

1.  Remove dependency on ant-contrib in downloads.xml and update README. [https://issues.apache.org/jira/browse/FLEX-35]
2.  Download playerglobal.swc to target the 11.1 APIs.
3.  In modules, make targets consistent with frameworks so downloads->thirdparty-downloads and downloads-clean->thirdparty-clean and add super-clean target.
4.  Add rat-check target to top-level build file.  This uses an Apache task to check for missing licenses.  The excludes still need to be filled in.