Revert "Added configuration options for AJAX method from @kuon. Closes #523"

This reverts commit 44d3b60967e1781cd184132954c3c209a607c865.
Added configuration options for AJAX method
Re-build ajax.js from source
Fixes #528
Delete unused test runners

`$ npm test` was still running them, causing duplicate test runs.
Merge branch 'relation-fetch' into dev