Fix opt crash of local_gpu_lazy_ifelse.

Reported by Ryan Price
better error message.
fix crash on GTX285 for new function recently added.
Fix test crash in DebugMode. We make the toposort of the same type as all other places.

It was a set, not it is now a list. This cause problem in the error handling code where we try to get the index in a set. That isn't defined.
Update comment.
Fix import that cause test crash
pep8
Make a test do what it should.

It was passing event if it tested the wrong stuff. After fixing it
still work correctly.
fix dtype problem in a test.
Fix GpuConv error reporting. The error was raised in the next executed apply node when we detect the input to be None instead of CudaNdarray.

this fixes gh-786.
Make the inputs shape and strides printed by default when there is an error.

Also print the inputs type.

exception_verbosity now only add the debugprint that now also have the print_type parameter
Add todo comment.
small fix that caused error during error reporting.
add thunk.inputs and thunk.output automatically at many places.
Correctly handle the case where a thunk don't have an inputs fields.
Merge pull request #1441 from nouiz/fix_opt_crash

Fix opt crash of local_gpu_lazy_ifelse.