LP#1010027: more internal options for xul lists

specifically, give fm_columns a sort_headers flag for alphabetizing the columns
returned by label; and delete_me flag for omitting a column definition entirely

Not all xul lists are using fm_columns yet

Signed-off-by: Jason Etheridge <jason@esilibrary.com>
Signed-off-by: Jennifer Pringle <jpringle@sitka.bclibraries.ca>
Signed-off-by: Ben Shum <bshum@biblio.org>
LP#1010027: tweak patron columns in patron search interface

specifically, remove the Mailing Address and Billing Address columns that come
off the actor table, since they are redundant with the Mailing Addr: Address ID
and Billing Addr: Address ID columns that come off the address table.

Also, alphabetize the columns coming directly off of the user table. The columns
coming off the library card and address tables remain unsorted; I believe their
order is as listed in the fm_IDL.xml file for their corresponding fieldmapper
definitions.

Signed-off-by: Jason Etheridge <jason@esilibrary.com>
Signed-off-by: Jennifer Pringle <jpringle@sitka.bclibraries.ca>
Signed-off-by: Ben Shum <bshum@biblio.org>