*) Easy patches: synch 2.4.x and trunk

  *) Easy patches: synch 2.4.x and trunk
         - server: Use apr_size_t instead of int to harden against overflows
         - mod_http2: DOXYGEN has nothing to do here, just remove this
                      strange "#if defined(DOXYGEN)"
         - test: make the compiler happy when using --enable-maintainer-mode
         - mod_proxy: Fix format string type check
         - mod_http2: Fix comment, no functional change
         - <various>: Remove unnecessary APLOGNO() use in TRACE-level logging
         - mod_cache_socache: Update comment only, to remove reference to
                              session cache
         - mod_dav: Fix error message formatting if an unauthenticated user
                    tries to use an authenticated user's lock token
         - <none>: trigger ci
         - server: Fix typo in comment

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1922956 13f79535-47bb-0310-9956-ffa450edef68