Merge pull request #78 from alxdarksage/develop

Support for row deletion, full use of PDRow/Value objects, full use of converters, bug fixes.
Merge pull request #79 from alxdarksage/develop

Small fixes, and screenshots to determine why tests are failing on Hudson
Merge pull request #80 from alxdarksage/develop

Instrumenting the heck out of the failing tests.
Moving form elements to use PD column descriptors. Changed admin function to only create descriptors and columns that are missing (descriptors can be updated when that is added).
Merge branch 'develop' of https://github.com/Sage-Bionetworks/Bridge into develop
Adding page to update trackers based on spec changes, or to warn user when there is a difference and the database will not be updated (columns are immutable).