Merge branch 'master', remote-tracking branch 'upstream/master'
fixed test_sim_ocl imports
Merge branch 'master', remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
clra_nonlinearities.py:plan_lif now acts on raggedarrays.

- I created a test for this function, comparing with the Numpy version
- I also added some basic tests for CLRaggedArray
- added a to_host function for CLRaggedArray
The LIF nonlinearity is now fully working.

- I've added a helper function that should make it easy
  to add more nonlinearities.
- This helper function allows for either one kernel per computation
  or one kernel doing a few computations.
- The only thing left to add to the LIF is upsampling.
Added upsampling for LIF neurons.
Minor fixes.

- Split up clra_nonlinearities:_plan_template it's easier to read
  (but still one function)
- Fixed to_host function in CLRaggedArray so it's more efficient
- Added host-side caching to CLRaggedArray, as discussed with @jaberg
- Added some more tests for CLRaggedArray
Changed d[A-Z] to cl[A-Z] for improved legibility.
Fixed bug with OCL plan_direct
- OCL now passes all test_simulator tests!
- I also fixed a little inefficiency in the clra_gemv loops
Removed old code in clra_gemv and suppressed some output
Fixed sim_ocl:plan_lif. OCL now passes all of test_ensemble!

- To do this, I added more flexible parameter support
  to clra_nonlinearities.