JSON for a brix activity proposed by mjl. Also a 1st pass at using it for kantorowski by Young Suk.
Some alternate ideas for activity config, with a new hookupActions section for each container

I did not finish going through the Kantorowski example to use hookupActions everywhere I think they may be used. I did do a few though.
Merge pull request #84 from mlippert/activityconfig-doc

Activityconfig doc