If one of the "then" elements is a TensorType, and the corresponding
element in the "else" branch is a compatible type, or vice versa,
convert it into TensorType, so both have the same Type, and the
output Type can be determined.

This should fix a problem reported by Ian.
[Commit amended to fix problem spotted by Fred]

It should work similarly to filter(), but on symbolic variables,
returning equivalent variables of the current Type if they are
compatible.

Fixed import crash in optimizations

CCW#37: REVIEW/TEST/DOC theano/sparse/sandbox/sp.py:RemoveO

CCW#37: modified theano.config.mode value under which assertion of application of the optimization is done.

Test using None in slices in local_subtensor_merge

Fix ticket number (oops).

Replace refs to Trac tickets with Assembla

Update dev start guide

Update the online doc about max, min,... function.

Finished square diagonal op

Check blas improvements

docstrings for the pinv op

Improved overall presentation

Fix subtensor merge

The formula for getting an element from an index in a reversed sequence
was wrong.

- Simplify and move test case for the bug reported by Razvan
- Add more general test of merging tensor[slice][index]