[BUG] Fix bug introduced yesterday, fix FFT conv optimization and small pydotprint fix.

no news
- fix a test in FAST_COMPILE
- fix the fft conv optimizer to have higher prio then the default gpu conv optimizer.
- fix bug introduced yesterday in an optimization.

news.txt
internal, added LocalSequenceDB and LocalSeqOptimizer (Frederic B.)

The default is:
if dnn avail and gpu support it, use it. Otherwise use gemm.

So, if the user specify fft tags, it should be done before the default logic.

We can't enable fft by default. The problem isn't the default, but allowing all combination that we configure via optimization tag.

If the optimization had access to the tag used, we could make this simpler. Or use a separate Theano flag? Could make make an optimization tag with a parameter? like gpu_conv=default, gpu_conf=fft, ... This is mostly a flag, but could be used per theano function.