re-initialized feature_definitions on refresh
allow datamodel users to specify different source suffixes (i.e. collections, tables).  datamodel.json points at root of database
removed unneeded
refactored logic into models
refactoring lookups and tumor_types
refactored webapp, router, topbar loads
renamed events
added lookups
defined UserPreferences model
cleanup
readying loading of genes through lookups
shifted to use genes lookup
fixed tumor types menu
refactored datamodel loading logic
fixed tumor type lookup
refactoring selected_tumor_types logic
differentiating queries by tumor type
making tumor_types an internal lookup source
refactored data and template loading
cleanup labeling and layout