buddy allocator for sl_malloc. Configurable at thread heap creation time. Need optimization for higher perf.

realloc'ing slap_known_controls.

LDAP_OPT_X_TLS_CONNECT_CB and LDAP_OPT_X_TLS_CONNECT_ARG
with int (LDAP_TLS_CONNECT_CB) (LDAP *ld, SSL *ssl, SSL_CTX *ctx, void *arg)
To be called whenever the client library allocates a new SSL* handle.

add more semantics to the "type" field; fix a bug in anonymous operations; treat children aci_mask() as internal searches

move ACIs under a dynamic infrastructure that allows run-time loadable custom access control logic (needs work)

instead of recycling thru avl_find/avl_delete/avl_insert

using backend-specific locks

add exop_is_write() macro for detecting exops that modify a target entry