Backport from HEAD:

* acinclude.m4: Pick up OpenSSL libs/cflags from pkg-config.

* modules/ssl/ssl_engine_io.c (ssl_io_input_read): Fix potential
infinite loop in ssl_io_input_getline if connection is aborted without
inctx->rc being set.

* modules/ssl/ssl_scache_shmcb.c (ssl_scache_shmcb_init): Use an
anonymous shm segment by default or fall back on name-based shm.

PR: 18989, 21335, 29964
Submitted by: jerenkrantz, jorton
Reviewed by: jerenkrantz, trawick, jorton, nd, minfrin


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@104768 13f79535-47bb-0310-9956-ffa450edef68