Implementation no longer uses strtok_r(), it may be broken
or have an odd prototype.
Update configure not to check for strtok/strtok_r nor require
strtok_r to LDAP_API_FEATURE_X_OPENLDAP_REENTRANT.
add/merge as we now free strings agressively. Improved debug
message to include name of missing required attribute and added
check for 'operational attributes'. This check should be used
everywhere we need to test for operational attributes (add/modify).
Also, enabled schema checking for tests (and fixed resulting
problems by adjusting oc.conf).