loadparm.c: Added #ifdef USE_LDAP around ldap code.

loadparm.c: Added #ifdef USE_LDAP around ldap code.
server.c: Moved %U, %G and %N into standard_sub() from standard_sub_basic()
          as only smbd knows about usernames. Also fixes problem with calling
          standard_sub_basic() from loadparm.c.
smbpass.c: Partial tidyup of machine_password_lock() code - not finished yet.
util.c: Moved %U, %G and %N into standard_sub() from standard_sub_basic()
          as only smbd knows about usernames. Also fixes problem with calling
          standard_sub_basic() from loadparm.c.
lib/rpc/server/srv_ldap_helpers.c: Added #ifdef USE_LDAP around ldap code.
lib/rpc/server/srv_samr.c: Added #ifdef USE_LDAP around ldap code.
Jeremy.