Make SequenceGenerator functional again

This involves bunch of changes in the core.
Merge branch 'rizar' of github.com:bartvm/blocks into bartrizar

Conflicts:
	blocks/tests/test_seqgen.py
Include *args and **kwargs in initialization call.
Fixed problem with update_instance, PEP8 fixes and Python 3 compatibility, also fixed repr_attrs for cases where repr is used before __init__ was called
Run Travis with both floatx=32 and floatx=64
Get coverage correct
Lower allclose tolerance for float32 tests
Update documentation
Bug fix
OrderedDict instead of dict to have fixed order of states
Wrap Application class in order to maintain documentation from application methods
Add six to requirements.txt in order to build RTD
Markov Chain demo works

I had to some changes in the core, specifically
push_initialization_config and push_allocation_config are now
recursive. I addition I commited some helpful debugging routines.
Merge branch 'sequence_generator' of github.com:bartvm/blocks into seqgen
Update documentation structure
Merge branch 'sequence_generator' of github.com:bartvm/blocks into sequence_generator
Fix documentation copy error
Sinewave generator is functional again.

+ speeding up FakeAttentionTransition by postponing scan to later stages
Unused imports
Fix stupid bug in variable list preparation.