Remove any duplicate search fields of the same type
Cleaned up database backend search method
Made quotes more consistant
Don't run tests with wagtailsearch signal handlers enabled
Removed 'object_indexed' check from update_index command

Conflicts:
	wagtail/wagtailsearch/management/commands/update_index.py
Fixed a few more double quotes
Give some feedback from the add_bulk command
Set index:'not_analysed' setting on content_type field
Merge pull request #348 from kaedroho/searchchanges/bits-and-pieces

Search Changes 7 - Some small changes