Minor stuff

Thanks Olivier :) Is great to have someone like you involved in the project, that is able to notice and fix all the small details. 

additions and improvements to blas on both CPU and GPU (including GEMV, GER in blas_c)

Remaining scan errors

We should use optimization tags to enable, disable them. This also could cause problem on test in case there is a bug, teardown would not be executed per James comments.

It seems that even the last fix of the generated random numbers didn't do
the trick. The reason being same numeric instability.
I've change the operation to a sum, which, if you apply it recursevly is
less problematic then multiplying numbers

Fixed crash at exit time if cache was deleted

Fixed some tests broken due to exception verbosity

This commit also includes a few PEP8 fixes.

This test fails because of small numbers (the gradients are especially
susceptible to small numbers). Increasing the range from which we sample,
it doesn't mean that there will not be a seed there for which the sampled
numbers are small enough (or a few entries are small enough) to get in that
instability region

This tests are of the sandbox of scan that I want to change anyway..

Gpu properties

Improved scan error message

I think that we can't really use iter(x) as suggested by David, because we want to iterate over the items.

Two improvements:
- An explicit error is raised if the lambda expression used in scan
  returns something that is not made of Theano variables (which may
  happen for instance when someone returns a constant value).
- An error is always raised when failing to parse the return value of
  the lambda expression

-renamed TestGer_local_gemm_to_ger to TestGer
-changed the Ger.infer_shape methode with ger.perform
 This make test of cpu and gpu ger op easier and follow what is done most of the time
-Moved tests in TestGer_make_thunk to TestGer and use theano.function
 This was needed to make them work on cpu and gpu
-make TestGer always call call the compiled function