declare return value of index_mask() to be slap_mask_t, also get rid of extraneous code in for() loop

specifically check for NULL return from ldap_int_thread_delist(). Also, fixup comment to get rid of compiler warning.

s/got_max_ssf/got_min_ssf/ thinko fix when checking for minssf. In this case, minssf was never set, and would cause maxssh to be set in error

Relax user-only options on TLS_RANDFILE and TLS_REQCERT

Add NameAndOptionalUID/UniqueMemberMatch handlers