Handle Rummager not returning description

If a record in Rummager's search index doesn't have a description then
it will omit the field completely rather than returning a blank value.
That causes the `fetch` to blow up, so default it to `nil`.
Merge pull request #86 from alphagov/handle-empty-dsu-descriptions

Handle Rummager not returning description
Select box arrows are upside down, so switch
Merge pull request #88 from alphagov/fix-arrow-direction

Select box arrows are upside down, so switch
Swap 'and' for 'or'

So that search result descriptors make sense i.e.

3 cases that are open and closed

becomes

3 cases that are open or closed
Merge pull request #89 from alphagov/change-and-to-or

Swap 'and' for 'or'