Branch for fixing issue 1965 in iD project
https://github.com/systemed/iD/issues/1965

Modify template for tasks
Add GPX export route, view and (empty for now) template
Fill in the GPX template and test the generated file in iD/JOSM
Pass the job_id parameter to the template
Convert tabs to spaces in template file
Merge pull request #166 from dvenza/fix_issue_iD_gpx

Implement a GPX link for each task