Use LDAP_VFREE and friends. Other misc code cleanup.

build/main.dsw

include/ac/string.h

libraries/libldap/disptmpl.c

libraries/libldap/dsparse.c

libraries/libldap/getfilter.c

libraries/libldap/ldap-int.h

libraries/libldap/os-ip.c

libraries/libldap/references.c

libraries/libldap/request.c

libraries/libldap/sasl.c

libraries/libldap/schema.c

libraries/libldap/sort.c

libraries/libldap/srchpref.c

libraries/libldap/string.c

libraries/libldap/tls.c

libraries/libldap/ufn.c

libraries/liblutil/ntservice.c

servers/slapd/schemaparse.c