Improve SpiNNaker API

[mundya]

The SpiNNaker binary will currently read a routing table from SDRAM, minimise it, and dump that table back to SDRAM.

Ideally we want to:

• sort the routing table prior to minimization (see desktop wrapper)
• set the default table size to the largest block of free TCAM
• dump the finished table to TCAM (optionally with a given app_id)

Stretch goal:

• Implement m-Trie, if the APLX is on core 1 use m-Trie, use OC on core 2, ...