Update example container to dynamically create rows of apps

[brianbaker]

Original discussion can be found https://groups.google.com/forum/?fromgroups=#!topic/openf2/TYBuHegEKfQ

The example container could be enhanced by creating rows of apps (with max grid width of 12) instead of putting all apps inside of a single row and allowing the browser to float them.

[markhealey]

Reopening w/ rollback to r1.1.2