Merge r1720129, r1723295, r1733088, r1733089 from trunk:

Merge r1720129, r1723295, r1733088, r1733089 from trunk:

* mod_ssl: Free dhparams when getting DH params. This fixes issue when
  SSLCryptoDevice does not get unregistered because of non-zero refcount
  during the mod_ssl unload happening on httpd startup.

mod_ssl: follow up to r1720129.
Free ecparams read from certificate file(s) on startup.

Follow up to r1720129 and r1723295: CHANGES entry.

Rephrase r1733088 since leaking means horrible things in cryptography.
This is not a security fix :p
Submitted by: jkaluza, ylavic, ylavic, ylavic
Reviewed/backported by: jim

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1735770 13f79535-47bb-0310-9956-ffa450edef68