Squashed commit of the following:

Squashed commit of the following:

commit 39fdd181d95d2c39a3ea1ca330b10a99a92b961f
Author: Evan Prodromou <evan@status.net>
Date:   Mon Nov 29 10:37:49 2010 -0500

    use cache key prefix for router cache key

commit 4cb9e56941922489b83d6425c059cf770991e68f
Author: Evan Prodromou <evan@status.net>
Date:   Mon Nov 29 10:31:21 2010 -0500

    use a unique hashkey based on the software version and loaded plugins

commit 44458b48aef719543e11f83b41fded65cbcb8be9
Author: Evan Prodromou <evan@status.net>
Date:   Sat Nov 27 17:04:15 2010 -0500

    cache the NUM object

commit 809c188307a9b4ada15f3d7fa573a6034341efef
Author: Evan Prodromou <evan@status.net>
Date:   Sat Nov 27 15:44:12 2010 -0500

    accelerate routing by pivoting paths on actions