- Modified test to make sure this works

- `theano/gpuarray/opt.py` added optimisation to include new op
- `theano/gpuarray/subtensor.py` added op
- `theano/gpuarray/tests/test_subtensor.py` added simple test case

speed up tests, fix compiledir cache crash and old unpickling.

Added the tri-gamma function.

Params for Gemm, CGer, CGemv

Gradient for matrix pseudoinverse

Work around erroneous dnn_conv results with algo small an large batches

Buildbot testsuite names

removed part of _optcheck_fgraph and called std_fgraph instead

(replace algo `small` by `none` if necessary).