Neuron ensemble generation speedups

- inside ensemble_origin.py
  - removed theano functions for generating sample points
  - added option for rate mode A matrix generation for LIF neurons
- cleaned up the lif.py and lif_rate.py files
- cleaned up ensemble.py
Add set_alias() to Network and Subnetwork
Merge branch 'master' of https://github.com/ctn-waterloo/nengo_theano
Fix cache to handle different array sizes (fix #50)
faster computation of Ginv
Updated test_enc to run for longer
script changes, don't auto-run tests now
New scripts and thalamus template.

- Also some learning updates
Fixed learning errors, updated scripts

- learn functions were being computed improperly
- showed up when connecting different sized ensembles together
- updated scripts and learn test
build time speedups
removed lif_op, simpler and faster now
Fix for unsupervised learning
Simulation runtime speedup

- made sure everything was float32
- removed lif_op, map_gemv, and Case2,
  replaced with theano code
- TODO: replace Case3 with theano code
Updated tests/templates/scripts
quick fix for ensemble...to make things work
Renamed folder, fix #33
Moved files out of nef_theano, and updated Network

- moved files into nengo theano folder
- updated tests, scripts, and templates
- must run setup.py before anything runs now
Network updates
- added connect_neurons, simplified transform logic
- updated tests and scripts accordingly