Deterministic Traversal / Sorting Strategy

[alexsb]

We want to have a user-chosen, deterministic traversal and sorting strategy. The main problem right now is the decisions of which leaf to visit first.

As far as I know, this is alphabetical right now; I'm not sure what effect the sorting has. We need to do this based on data; alphabetical is one option, but we want many others.

Ones that work independent on type:

• Alphabetical
• By Degree
• By Pagerank
• By Type (alphabetical)

If it's based on the attributes of a type, I'd suggest to put the items of the sorted type first, sort them, and then follow by all other types.

[alexsb]

For now, sort children alphabetically in extract tree.

[cnobre]

done.