Comment 1 for bug 1021642

Comments from discussions with Dr. Monelli and Dr. Danciu:

Results:
- one XML result file per site per imt; there is no reason to group by sites
  - that means one uiapi.output record per set of matrices for a given site/imt
- it would be nice to have a `sites_file` parameter, defining a CSV file containing all of the site definitions; having 20 or 30 sites defined on one line is error prone and tedious (and hard to read)
- revised result XML prototype: http://pastebin.com/QdxtMTwF
  - note that the binary/XML hybrid has been dropped

Calculation:
- Phase 1: Compute hazard curves, using the Classical approach, parallelizing over sources
- Phase 2: When all curves are computed, compute disagg matrices, parallelizing over sites; we cannot parallelize over sources in this case