Enforce single quotes in hound

After trying out double quotes, single quotes are easier to type and can
be changed to double quotes with `cs'"` using the `surround.vim` plugin.
Remove preserving delivery sort in a cookie

This was meant to preserve the user's preference when viewing deliveries by
date. The most meaningful way to view deliveries by default is newest
deliveries first so there isn't as much of a presedence to sort by
oldest first when visiting `/deliveries` with no specified filter.
Remove unneeded helper methods in `DeliveriesController`

Leverage `paraphrase` to filter and specify defaults for query params if
none are specified removing the need for `delivery_search_params` in
favor of using `@query` in the view to read param values.

Remove call to `Delivery` constant in `deliveries/new.html.haml`. Build
a delivery with receipts for each recipient in the query params in the
controller removing the need for `receipts_for_new_delivery`.