Added N. Ireland from their centralised site - I haven't added all authorities as it's a long list and I wasn't sure it could cope with it. At the moment only Belfast has applications. 

The councils are listed below and can't be added separately, they all use this site for planning applications.
    Causeway Coast and Glens
    Mid and East Antrim
    Antrim and Newtownabbey
    Belfast
    Lisburn and Castlereagh City Council
    Ards and North Down
    Newry, Mourne and Down
    Armagh, Banbridge and Craigavon
    Mid Ulster
    Fermanagh and Omagh
    Derry City and Strabane District

Added Nottingham

Should we even bother parsing all these fields from the search results pages given that we'll get them on the deeper scrape anyway?

We need to test a group of Idox sites to see how these parameters are used in practice.

This structure allows us to add other missing fields easily if necessary.

Like "Not available" in Greenwich.

UKPlanningScraper#search method is now UKPlanningScraper::Authority.scrape.

It's nicer to type.