Complete and test participant parsing

Populating complete and untested
New categories and metrics used in bridges dataset

first pass, may need some ironing out
Add info metric
Improve participant parsing and start sessions
Parsing for all session headers
More work on asset parsing, generalize stage support
criteria typo
Merge branch 'master' into bridges
Fix down evolution order for new categories
Complete population for bridges ingest

Untested
Merge branch 'bridges'