Upgrade React and related packages to 0.12.1

Remove @jsx pragmas (not necessary anymore) and use `render` in lieu of
renderComponent (which is being deprecated).

fixes #207
Update mocha runner for no JSX pragma
Update dpxdt screenshots (changed due to #285) and update SQL (changed due to #290)
Fixing examine.png
Change README.md mention to DEVELOP.md
Change DEVELOP.md URL
Merge pull request #292 from hammerlab/update_dpxdt

Update dpxdt screenshots (changed due to #285) and update SQL
Merge pull request #293 from hammerlab/edit_readme

Edit pdifftests README
Treat underscores as characters
use arguments.length
Merge pull request #298 from hammerlab/complete-underscore

Treat underscores as characters
Address CR
Merge pull request #289 from hammerlab/issue-207-update-to-react-0-12

Upgrade React and related packages to 0.12.1
Test for ExaminePage, fix two bugs it found.
code review
remove a few more @jsx pragmas
Merge pull request #294 from hammerlab/moar-tests

Test for ExaminePage, fix two bugs it found.
fix all lint errors in /tests
tests working backwards & forwards
run tests forwards & backwards on travis