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* Python 2.6 support dropped
* Fixed a memory leak bug (a reference to thread-identity object would be kept
forever after a request would be served by particular thread; without greenlet
package installed thread ids (numeric values) are used so the internal
dictionary of thread local storage grows forever; when greenlet package is
installed greenlet objects are used as thread identities by Werkzeug so on top
of the internal storage growing infinitely all objects referenced by those
greenlet objects are kept alive; keywords: Eventlet, Gevent, GreenThread). See
GH issue 9 and pull request 11, thanks to Zi Li for the fix