Support now for deleting rows in the trackers, from the table or index view.
A number of small bug fixes
Merge branch 'develop' of https://github.com/Sage-Bionetworks/Bridge into develop
Switched to use of ParticipantDataValue, removes some object --> string conversion logic
First part of a refactor to use the ParticipantDataRow/Value objects (not converting them until display, ultimately) and consistently formatting/converting tracker data using the FormElement converters.
Merge pull request #78 from alxdarksage/develop

Support for row deletion, full use of PDRow/Value objects, full use of converters, bug fixes.