Normalize edge "order" and "size"

[leotrs]

The words "order" and "size" are used throughout the codebase to refer to the number of nodes in an edge (where order = size-1). I'd suggest we choose one and remove all instances of the other. For example, we have H.edge_size but H.edges_of_order.

[leotrs]

FWIW, I'd rather keep order so that we don't have problems when implementing simplicial complexes.

[iaciac]

I'm more than OK with order!

[maximelucas]

Good point. I'm fine with order too.

[nwlandry]

I'm okay with doing this, but will admit that this will be a bit of habit for me to break :). Along these lines, is the biggest remaining change the IDDegreeView class?

[nwlandry]

One thing that probably will need to change is that we may not be able to effectively use IDDegreeView class as a base class if we choose to use edge_order instead of edge_size, because degree and edge order will be off by one from each other.

[leotrs]

Oh jeez that complicates things.

[leotrs]

Related to #82

[nwlandry]

This was fixed with EdgeStats, no?

[leotrs]

Kind of. We now have both order and size, so any EdgeStat (or any other part of the codebase that is aware of the stats package) can choose which one to use. So on that front we are fine.

What has not been addressed is the fact that currently, SimplicialComplex inherits from Hypergraph and that is Very Messy And Bad.

I guess this particular issue is about the first problem, not the latter, so let's close this. For more discussion of the latter, continue on #82 .