The LDAP controls and extended operations (EXOP) has been merged upstream
with some modifications. The patches backports upstream code to php70
and php71, with additionnal EXOP REFRESH support that is missing for now.
Interractive methods such as OTP use the ldap_sasl_bind() callback with
SASL_CB_ECHOPROMPT or SASL_CB_ECHONOPROMPT instead of SASL_CB_PASS. Add
the cases and treat them like SASL_CB_PASS for PHP 5.4.x and PHP 5.5.x.
The exop patch for PHP 5.6.x is broken right now and will be updated later.
Do not force-define HAVE_LDAP_SASL, since the PHP configure script
actually takes care of that one. This lets us build with the exop
option enabled while sasl is disabled.