Merge of r771160,1772576 from trunk:

SECURITY: CVE-2016-8740

mod_http2: properly crafted, endless HTTP/2 CONTINUATION frames could be used to exhaust all server's memory.

Reported by: Naveen Tiwari <naveen.tiwari@asu.edu> and CDF/SEFCOM at Arizona State University

mod_http2: wseaking cleanup assertion on streams that have never been scheduled


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1772579 13f79535-47bb-0310-9956-ffa450edef68