Changes with nginx 1.9.5 22 Sep 2015
*) Feature: the ngx_http_v2_module (replaces ngx_http_spdy_module). Thanks to Dropbox and Automattic for sponsoring this work.
*) Change: now the "output_buffers" directive uses two buffers by default.
*) Change: now nginx limits subrequests recursion, not simultaneous subrequests.
*) Change: now nginx checks the whole cache key when returning a response from cache. Thanks to Gena Makhomed and Sergey Brester.
*) Bugfix: "header already sent" alerts might appear in logs when using cache; the bug had appeared in 1.7.5.
*) Bugfix: "writev() failed (4: Interrupted system call)" errors might appear in logs when using CephFS and the "timer_resolution" directive on Linux.
*) Bugfix: in invalid configurations handling. Thanks to Markus Linnala.
*) Bugfix: a segmentation fault occurred in a worker process if the "sub_filter" directive was used at http level; the bug had appeared in 1.9.4.