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.
Catch all exceptions, not just {OS,IO}Error in IOLoop.remove_handler.

Attempting to remove a non-existent fd raises IOError on epoll
but KeyError on kqueue; this change swallows any exeption to make
both platforms consistent.
curl_httpclient: don't call remove_handler if we never added it.

Re-order IOLoop and self._fds operations for consistency.
Don't catch and hide exceptions caused by callbacks in http client
add_callback now takes *args, **kwargs.

This reduces the need for functools.partial or lambda wrappers, and
works better with stack_context in some cases since binding the
arguments within IOLoop lets it see whether the function is already
wrapped.
Add forgotten release note.
Remove some now-unnecessary calls to functools.partial
TwistedIOLoop now supports overriding handle_callback_exception.
Run AsyncHTTPClient callbacks on the IOLoop for a clean stack.

Closes #652.
Merge remote-tracking branch 'rhettg/master' into work
Replace a couple of contextmanager functions with ExceptionStackContext.
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'