Add causes to filter

 * add cause radio buttons to view
 * add causes to projects_json
 * add helper methods to produce arrays of causes and technologies so that radio buttons can be iteratively generated instead of hard-coded
 * add abstraction to view (input buttons iteratively generated)
 * add extremely non-DRY JavaScript that allows users to filter by technology and cause with aforementioned radio buttons
Merge branch 'master' of https://github.com/keaty/codemontage into improve-project-ordering
Merge pull request #4 from keaty/improve-project-ordering

Improve project ordering