Changes
- New run possibilities in addition to JATOS run, MTurk and MTurk Sandbox run: open standalone run, closed standalone run, and tester run
- New worker types: open standalone worker, closed standalone worker, tester worker
- jsPsych example featuring jsPsych library (www.jspsych.org)
- renaming studies folder to study_assets (including the URL path part)
- many bug-fixes