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.
Remove whitespace/control-character check from RequestHandler.redirect.

Control characters (and newlines and tabs) will be caught in
set_header (which will raise an exception instead of silently
stripping them).  Spaces will now be allowed through, producing
invalid urls, but at least they won't mess up the header framing.

Closes #617.
Release note updates
Add a missing stack_context.wrap in SSLIOStream.connect.

Run some of simple_httpclient test in both HTTP and HTTPS modes, which
would have detected this bug.

Closes #787.
Add a close method to Resolver and use it where necessary.

This fixes a thread leak when running the test suite with
ThreadedResolver.
Merge pull request #1 from facebook/master

merge master from facebook tornado
fixed bug when raise error in options
comparison to None should be 'if cond is not None'
Make options instance more dict-like.
Use 'get_version' to calculate static file hashes.
(incomplete) Honnoring Range request header
Add test for option redefinition error.
Fix bytes/str issues
Dereference the current YieldPoint as soon as it resolves.

These references could otherwise keep a chain of old references alive
(test code: https://groups.google.com/group/python-tornado/browse_thread/thread/37d3928817e4924d)
Merge branch 'branch3.0'
Set Accept-Range header, return 406 on invalid range