Add scrapers for Merton and Conwy (PlanningExplorer)

Add Blackburn and Greenwich (acolnet sites - patch from Peter Collingbourne.
Fixes to Ocella parser (also from Peter). Adds Bridgend, Castle Point, Great Yarmouth, Havering).
Fix typo and escaping in getinvolved (patch from David Sheldon).

This site is absolutely rubbish: 

1) It's impossible to link to the info page - needs a cookie. I've put a link to the search page for the moment.
2) Many applications have no description. I've put the text "Description Missing" when this happens.

we don't have postcodes.

Encode all output as UTF-8.

my machine...

Repeat to self: haggis is on python 2.4, haggis is on python 2.4, ...

It looks like there has been an update to most of the Acolnet sites.
I'll need to go through and look at the rest...

New Forest DC 
Bolton

This allows us to do lots of sites without custom scrapers.
We also get a few that we didn't have before:

Bridgnorth
Canterbury
Guildford
Mid Suffolk (no postcodes)
Southwark