RFE: per-workstation login timeout setting

[Nathan Eady]

Currently, the setting for how long a (web staff client) session takes to time out, is at the organization level. Effectively, this means a cataloger working in the office area and staff member logging in quickly at an airport terminal to check on something, have the same timeout.

Ultimately, I'd like to have the following settings:

 * an organization-wide maximum, which can be the current setting

 * an organization-wide default, which could be set much shorter, to cover
   cases like a one-time login on a non-library computer. Workstations in
   a staff-only office area, for instance, could then have their timeouts
   set long enough to cover an entire shift.

 * a per-workstation setting that overrides the organization-wide default
   (but does not override the maximum).