Merge r1826687, r1827166, r1828210, r1828232, r1828687 from trunk:

Merge r1826687, r1827166, r1828210, r1828232, r1828687 from trunk:

Instrument 'bbout'

mod_http2: use proper ARP defined for formatting apr_off_t

On the trunk:

mod_http2: on level trace2, log any unsuccessful HTTP/2 direct connection upgrade
     with base64 encoding to unify its appearance in possible bug reports.

On the trunk:

* mod_http2: calculate unencrypted connection sniffing base64 only when log level is at required height. [Ruediger Pluem]

On the trunk:

mod_http2: accurate reporting of h2 data input/output per request via mod_logio. Fixes
     an issue where output sizes where counted n-times on reused slave connections. See
     gituhub issue: https://github.com/icing/mod_h2/issues/158

Submitted by: jailletc36, icing, icing, icing, icing
Reviewed by: icing, jim, ylavic

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1832489 13f79535-47bb-0310-9956-ffa450edef68