Upgrade compass + sass

Summary:
- Bump compass, sass and grunt-contrib-compass versions
- Fix fonts_dir in compass configs
- Turn on source maps
- Update font-awesome/_path to match docs and avoid errors
- gitignore source maps

This seems to cause some changes in the way the workspace menu works, including breaking scrolling.
If we want go with this and upgrade sass and compass, I'll had this to Seth to fix styling issues

Test Plan:
- `grunt compass`
- Check UI

Reviewers: seth, shadowhand

Reviewed By: shadowhand

Maniphest Tasks: T186

Differential Revision: https://phabricator.ushahidi.com/D147