Implement additional error handling in utils.import_object function
Merge remote-tracking branch 'upstream/master' into import-object
import_object will raise standard ImportError even in case of Value/Attribute error
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.
correctly handle empty POST parameters
Allow add_handlers() to append to existing hosts.

This change removes the restriction that all handlers for a given host
pattern be registered in a single call to add_handlers().
Merge branch 'master' into append-handlers
_get_host_handlers() now returns all host matches.

This approach has more clearly defined precedence rules than the
previous insertion-time strategy implemented in add_handlers().

It also correctly leaves pattern matching in the hands of the regular
expression evaluator as opposed to directly comparing pattern strings.
Avoid setting IOStream.error to wrong exception, close #651
Fix typo in releases/next.rst
Merge pull request #654 from davidwilemski/patch-1

Fix typo in releases/next.rst
Merge remote-tracking branch 'jparise/append-handlers' into merge
Release notes for add_headers change
Merge remote-tracking branch 'ajdavis/issue-651'
Allow tuples for the IOStream.close exc_info argument.

Update release notes.
Test with twisted 12.3