Revision 1546690

Remove obsolete TODOs for mod_ssl:

No, we don't - it was removed in r90511.

DH keys are changed for every connection, SSL_OP_SINGLE_DH_USE
is applied since mod_ssl's initial commit (r88988).

We no longer have our own CRL callback (delegated to OpenSSL
as of r1165056), so this is effectively moot.

ssl_engine_pphrase.c needs to be simplified, not blown up further
(see also https://issues.apache.org/bugzilla/show_bug.cgi?id=24031,
which few [if any] people really seem to miss)