Whitespace, alignment
Comment out redundant `accepts_nested_attributes`
Simplify use of optional locals in views
Remove obsolete parameter
Use `object`/`collection`, not `model`/`models`

Use `object` and `collection` instead of inappropriately used `model` and `models`, respectively.

`model` should be used instead of the strange `klass` to store a model (which is a class).
Use `model` instead of `klass`
Experiment with main menu template
Associate TicketBook with Membership (1st commit)

Basic chenges to associate TicketBook with Membership instead of MembershipType, and to nest TicketBooksController under MembershipsController.

Made the tests pass.
WIP
WIP
More intelligent 'new' links for memberships