Store entity counts in a search hit

I would like to request the following feature:

To pre-compute (particularly, during full-text indexing) and store no. child 
pathways, interactions, other (biopax Entity) in the cPath2 biopax Lucene index 
(alternatively, can just store the number of all child Entity type objects) for 
all documents of types: Pathway, Interaction (including sub-classes), and 
Complex (or, why not, - can do so for any Entity sub-class objects, which might 
be useful to see how many members are there in generic physical entities...). 

We used almost the same approach for computing and storing parent pathway URIs 
in the 'pathway' index field, returning that via SearchHit.pathway xml element.

Indexing is one thing; modifying the search XML schema to include the 
corresponding new elements (or attributes) will be another change to do 
(luckily, this seems backward compatible web service API/schema change; old 
cpath-api and cpath-client versions should still be working with the updated 
XML results from the new server instance, ignoring new elements/attributes...).

Then, this new information can be shown on the (new, future) "Find/Top 
Pathways" web site page (/view#/pw/) and in the GUI of CyPathwayCommons 
(CyPath2) app for Cytoscape 3.

Original issue reported on code.google.com by rod...@gmail.com on 3 Jul 2014 at 8:46

Merged into: #171

PathwayCommons / cpath2

Store entity counts in a search hit #182