Adding support to override, via static_url, whether the generated URLs
should include the version signature or not.
Introduce StaticFileHandler.(get_content|set_headers) which reduces the
complexity of the HTTP GET handler of static resources.
Fixed syntax error in the altered StaticFileHandler.get() method
Move retrieval of absolute path to separate method which is also in
charge of validation.
Cache the computed absolute path to the requested resource in
StaticFileHandler. The cache is cleared on_finish of each request
in order to ensure recomputation on each request.
Fix typo in README
Merge pull request #739 from eguven/master

Fix typo in README
Fix the same typo in docs/index.rst
Expand docs for @asynchronous decorator and other cleanups.

Closes #742.
support ip lists in X-Forwarded-For headers
Unnecessary MozWebSocket in the WebSocket demo

WebSocket is implemented in all modern web browsers.
Merge pull request #745 from davidwilemski/xheaders

support ip lists in X-Forwarded-For headers
Don't try to run HTTPConnection._close_callback if it is None.

This was the case for WSGIContainer.

Closes #751.
Merge pull request #752 from oyerli/patch-1

Unnecessary MozWebSocket in the WebSocket demo
Expose IOStream's max_buffer_size, so we can set it in TCPServer and others.
Corrected or logic to make use of max_buffer_size if it is setted
Catch additional errors to prevent warnings logged when connections
are closed immediately after opening.

Closes #750.
Fix resolver implementation on Solaris.

Closes #766.
Remove reference to last task and his arguments in engine to free memory.
Avoid circular references in StackContext and ExceptionStackContext.