Implement method to assess relevance of links between pathways.
Ensure PDDocuments are closed.
Improve exception handling.
Make link relevance testing more comprehensive.
Add main method for scoring reactions by pathway link relevance.
Make general methods for reading from and writing to SBML files.
Merge branch 'feature/pathwayLinkRelevance'
Fix determination of starting relevant reactions when finding pathway links.
Move code out of the main class.
Cleanup.