More memory context tweaks

servers/slapd/acl.c

servers/slapd/aclparse.c

servers/slapd/add.c

servers/slapd/attr.c

servers/slapd/ava.c

servers/slapd/back-bdb/add.c

servers/slapd/back-bdb/compare.c

servers/slapd/back-bdb/delete.c

servers/slapd/back-bdb/filterindex.c

servers/slapd/back-bdb/index.c

servers/slapd/back-bdb/modify.c

servers/slapd/back-bdb/modrdn.c

servers/slapd/back-bdb/passwd.c

servers/slapd/back-bdb/proto-bdb.h

servers/slapd/back-bdb/search.c

servers/slapd/back-bdb/tools.c

servers/slapd/back-ldap/back-ldap.h

servers/slapd/back-ldap/config.c

servers/slapd/back-ldap/search.c

servers/slapd/back-ldap/suffixmassage.c