Pass src_properties and dest_properties in projection specifiations rather than whole projection
Fixed for recent commits
Multiple small fixes suggested by Tobias
Updated lancet submodule reference
Merge pull request #577 from Tobias-Fischer/projection_properties

Pass src_properties and dest_properties in projection specifiations
ChannelGeneratorSheet now available from topo.sheet
Merge pull request #578 from jlstevens/master

Updated Simulation to support class-based models.
Eliminated redundancy in projection access
Improved Simulation call method and added docstring
Fixed bug in definition of opponents
Fixed bug in path specification for projections
Context manager now uses param logging to silence warnings properly
Updated param submodule reference
Fixed bug in __repr__ of SheetSpec and ProjectionSpec
Updated dataviews submodule reference
Sheet ordering specified by setup_sheets if an OrderedDict is returned
Added a summary method to Model and Specifications for pretty printing

The _repr_pretty_ method uses the summary method (via __str__) for
pretty printing in the IPython environment.
Added a properties parameter to all Sheet objects
Instantiating a SheetSpec now sets the Sheet properties appropriately
Avoid creating decorators for class declared as abstract