fix: require sigdict elements to be arrays
enh: better strings for ref Ops
enh: name for DotInc in build_connection
First draft of context system and object syntax
Fixed the two examples
Changed context stack behaviour

Now any time a model is created it clears the context stack
and becomes the new default.
Quick fix to get spike probes working
All connections now stored in model

- Rather than on pre/post
- Removed all connections_in/connections_out code.
- Also fixed some unit tests that were failing.
Using ContextStack data structure

- ContextStack is a collections.deque subclass
Cleanup and PEP8 fixes

- Everything now follows PEP8
- Moved ContextStack to __init__ and removed context.py
- Moved Network class to objects.py to make importing cleaner
- Made some relative imports absolute imports,
  will try to always do this in the future
Replaced EnsembleArray template with a network

- This simplifies many things, as ensemble arrays are not longer
  a special case
Removing ConnectionList

This was only used in templates.EnsembleArray
Removed templates directory
Replaced usages of kwargs with actual args

This is to make errors come up earlier in model definition.

- This has already uncovered an error in the basal ganglia network!
Added import nengo.helpers
Remove nengo.templates import

Templates have been removed.
This breaks installation in master.
Combined DecodedConnection and Connection

- The behavior of a connection now depends on pre and post,
  either of which can be a node, ensemble, or neural population.
Fixed bug in rasterplot

- Never should have used an underscored attribute...!
Added .travis.yml for travis-ci

- Testing 2.6 and 2.7 for now
Fixes for certain environments

- Python 2.6, and non-Matplotlib environments
- Basal Ganglia test relaxed a bit