[RC5] extremely short work units

[Mikus Grinbergs]

Running OGR offline.  Like to have days and days and days between
contacts with the server.

Just now was given a bunch of work units that take TWO MINUTES each !!

I'm hesitating to set my "queue size" at 1000 -- what if on the next
download I were to get four-hour work units ?

These short work units make management of not-always-connected
systems a pain.

Bah.  mikus