Squashed commit of the following:

commit 533bc001
Author: Thomas Skovgaard Gielfeldt <thomas@gielfeldt.com>
Date:   Tue Oct 25 21:00:52 2011 +0200

    Removed update of processes and progresses.
    Readd indices to ultimate_cron_log.

commit 6b9ced60
Author: Thomas Skovgaard Gielfeldt <thomas@gielfeldt.com>
Date:   Sun Oct 23 10:32:55 2011 +0200

    Check rules before restarting queue.

commit b723b7bc
Author: Thomas Skovgaard Gielfeldt <thomas@gielfeldt.com>
Date:   Sat Oct 22 21:51:27 2011 +0200

    Made support of exportables optional.

commit 4682cccb
Author: Thomas Skovgaard Gielfeldt <thomas@gielfeldt.com>
Date:   Sat Oct 22 19:47:54 2011 +0200

    Removed unused/unnecessary code.
    Fixed loading of log data.
    Optimized preload.

commit b05d98ec
Author: Thomas Skovgaard Gielfeldt <thomas@gielfeldt.com>
Date:   Sat Oct 22 15:52:45 2011 +0200

    Don't clear variable cache on each cron run.

commit 352be738
Author: Thomas Skovgaard Gielfeldt <thomas@gielfeldt.com>
Date:   Sat Oct 22 15:51:58 2011 +0200

    Make hook data available to hook_cronapi()

commit 218335b1
Author: Thomas Skovgaard Gielfeldt <thomas@gielfeldt.com>
Date:   Thu Oct 20 19:03:41 2011 +0200

    Fixed warnings and "Unsupported operands" errors.

commit 48ac239d
Author: Thomas Skovgaard Gielfeldt <thomas@gielfeldt.com>
Date:   Thu Oct 20 18:55:38 2011 +0200

    Preliminary exportables support.