Blocks fix

[jbornschein]

@dribnet, I'm gonna merge your old fixes; The goal is to make the code run again with the latest blocks/fuel version.

[dribnet]

Yes, I just noticed that there's been a release in the last few weeks - probably a good idea to now pin this project to that release and update, etc. Thanks!

[jbornschein]

Great, Thnx!

[dribnet]

Note I have a lots of more experimental changes in my develop branch:

• ability to load custom datasets (local hdf5 files)
• support for non-square inputs (separate width/height options)
• new "dashboard" output ever 10 epochs
• support for lab colorspace
• updates to sample.py:
  • can set num rows/cols in cli
  • --flat option to "flatten" high dimensional latent space
  • --tight option for tighter spacing
  • cli options to set subdir and filename

Happy to discuss which of these might be useful to merge back to upstream master.