Created by: jmmastey
- adds a new
showoption to HasMany, an array that controls displayed columns - when that option is forwarded, respects it within the collection page object
- updates docs to expose the new option
The tests are pretty reasonable, with one reasonable exception: the new HasMany test is really mockist, which I can see other tests are not. If y'all have a more reasonable approach to testing that bit of logic, I'm game. I tried and ended up just asserting a bunch of trivial behavior.
Fixes #1108 (closed) and #1109 (closed)