Show attributes and values for SAMPLE columns

This adds an "uber column" of INFO, SAMPLE_1, ... SAMPLE_n
with respective attibutes/values uderneath them.

fixes #67
Definitely a reference. It won't cause React to re-render. It can cause problems if done willy-nilly, but I'm treating it as an immutable value here. Since I'm calling setState right here, it won't cause issues.