Merge branch 'binaries' into refactored-vertices

Conflicts:
	nengo_spinnaker/ensemble_vertex.py
	nengo_spinnaker/filter_vertex.py
	nengo_spinnaker/nengo_vertex.py
	nengo_spinnaker/receive_vertex.py
	nengo_spinnaker/simulator.py
	nengo_spinnaker/transmit_vertex.py
[Broken?] New fixed-point library, factor out filter code from vertices.

 * new fixed-point library integrated
 * Filters factored out of most vertices and handled centrally
Merge branch 'general-io-nodes' into refactored-vertices

Conflicts:
	nengo_spinnaker/simulator.py
[Bugfix] Error in filter routing table generation.
Should be transmitting unsigned values.
Fixes to `bitsk` in Python.
Added tests; fixed rounding
Merge branch 'master' into refactored-vertices
Merge branch 'master' into refactored-vertices

Conflicts:
	nengo_spinnaker/ensemble_vertex.py
	nengo_spinnaker/filter_vertex.py
	nengo_spinnaker/nengo_vertex.py
	nengo_spinnaker/nodes/receive_vertex.py
	nengo_spinnaker/simulator.py
Slight rearrange of module layout.

 - `vertices` module moved into `utils`
   - Filter components split out
`NengoVertex` and related functionality for automatic region generation.

 - Vertices subclass `NengoVertex`
 - Mark methods as `@region_*` to indicate tasks performed
Move `ReceiveVertex` over to using `NengoVertex`.
Add `with_filters` decorator for vertices.
Move `TransmitVertex` over to `NengoVertex` style, using `@with_filters`.
Renamed some components, slight change to build procedure.

 - `spinnaker_components/{rx,tx}` became `spinnaker_components/sdp-{rx,tx}`
   - Makefile modified appropriately
 - Makefile modified to write binaries to ../nengo_spinnaker/binaries without additional
   copy step.
 - `nengo_spinnaker/nodes/{transmit,receive}_vertex.py` renamed to `sdp_{transmit,receive}`
   - Classes renamed `{Transmit,Receive}Vertex` => `SDP{Transmit,Receive}Vertex`
     - All appropriate calls changed
`SDPReceiveVertex` `sizeof` returned bytes not words, corrected.
`Simulator` calls pre- and post-partitioning prepare functions on vertices.
Move Ensembles over to new Vertex layout.
Move FilterVertex to new layout.
Remove unused `VertexWithFilters` class.