Generate barcodes and push them into LDAP

Generate barcodes and push them into LDAP

Call the new custom API to open-ils.actor for generating barcodes;
accepts one argument, user ID, which gets the barcode set to their new
value. If no arg is passed, just generates a new barcode and returns it
(should be useful on the patron editor screen).

As far as pushing the barcodes into LDAP goes, I can't confirm that the
updates are actually working, because I can't see them, but the lack of
errors suggests that it's working.

Signed-off-by: Dan Scott <dscott@laurentian.ca>