Fix bug that was preventing indexing - used wrong variable name
Add some more files to the exclusion list

We don't need these in the output from jekyll
Tidy up selection/rejection criteria for pages in search
Move writing of search index file to new method
Rename search index file to .search-index.json

We need DirectoryWatcher (the gem jekyll uses to detect changes to files when in auto mode)
to ignore the search index file, otherwise we hit an infinite loop. Unfortunately that's
not very configurable so using a dotfile is the easiest way to achieve that.
Don't commit search index to git
Merge branch 'master' into avoid-indexing-loop-in-auto-mode

Conflicts:
	_plugins/jekyll_rummageable/indexer.rb
Merge pull request #98 from alphagov/avoid-indexing-loop-in-auto-mode

Avoid indexing loop in auto mode