Make sure sparse.dot returns the right dtype

This triggered a problem on platforms where int bitwidth is 32-bit.
Add test case reported on the mailing-list.

Import "all" to make test work with python 2.4

Accept other Variable Types (particularly Cuda ones) in sparse check

Add a test case that was reported on theano-users.

Fix clip grad

MPI Ops

One of the mpi tests needs to run a file in the theano file system.

It is now pointed to that file through the theano.__file__ attribute.

mpi_cmp -> mpi_cmps

fix incorrect test `y = x + x` -> `y = x + 1` to match expected output

remove old comments

(these functions moved in a rebase)

I'm currently using os.popen.
I tried using subprocess.Popen without success. Would appreciate tips.

Also removed infer_shape for now

I suspect that this is necessary to hold as an output

Revert "Merge pull request #995 from pascanur/fix_grad_scan_dtype"

This reverts commit 4ecb5a04, reversing
changes made to 8b088c69.

Fix grad scan dtype

Remove debug line following code review.