Merge r1544774, r1544812 from trunk:

Address a todo listed in
https://mail-archives.apache.org/mod_mbox/httpd-dev/200205.mbox/%3CPine.LNX.4.33.0205292300380.27841-100000%40mako.covalent.net%3E
"init functions should return status code rather than ssl_die()"

For diagnostic purposes, ssl_die() is still there, but instead
of abruptly exit(1)ing, it will return APR_EGENERAL to the
ssl_init_* callers in ssl_engine_init.c, and these will propagate
the status back to ssl_init_Module.


Followup to r1544774: do not ignore failures from ssl_server_import_{cert,key}
in ssl_init_server_certs

Submitted by: kbrand
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1560082 13f79535-47bb-0310-9956-ffa450edef68