Merge branch 'master' of ../tornado-util into HEAD
HH-38987 move tornado_util code into place and edit docs
patches for logging
HH-28175 force curls to make fresh connections every time
HH-32949 Perform URL Encoding request headers from IE
HH-35189 set header length cap to a more appropriate value

Conflicts:
	tornado/web.py
fix absent IOLoop running() method