get Open Sans font from Google CDN instead of local hosting (and include extended character sets)
Show all button for activity collections > 3 items

This commit introduces a "Show all" button when an activity is a
collection of more than 3 activities. By default, only 3 tiles are
shown. When the user clicks the button, all remaining tiles are
displayed and the "Show all" button is removed.
resolving merge conflicts
Merge branch 'refs/heads/oae-bootstrap3' into bootstrap3-issue3369
Merge branch 'bootstrap3-large-activities' of https://github.com/simong/3akai-ux into bootstrap3-large-activities
(Issue #3556) Adjust build process to not (try to) inline Google's font CSS imports
Follow up on activity improvements
Small comment follow-up
(Issue #3556) Add reference to r.js pull request that supports saner CSS optimization options
(Issue #3556) Add note to keep font URL synchronized with build optimization options
(Issue #3556) Add note re: installing fonts for local development
Center user and group thumbnails
Self review on large activity items
Merge branch 'bootstrap3' into bootstrap3-large-activities
Followed up on code review
Merge pull request #3637 from nicolaasmatthijs/bootstrap3-large-activities

Activity widget improvements
(Issue #3369) Make sure build optimization puts CSS @import at beginning of file
(Issue #3369) Move development section in README.md
Merge branch 'bootstrap3-issue3369' of github.com:sathomas/3akai-ux into bootstrap3-issue3369
Small documentation improvements