Update documentation/InitDb to use musicbrainz_unaccent extension
Update README to require Pg 9.1
Hyperlink INSTALL.md from README.md

GitHub supports hyperlinking in this form.
Require Pg 9.1 before doing any work in InitDb.pl
Install musicbrainz_collate as an extension
Remove PostgreSQL < 9.1 support from script/create_test_db.sh
Reintroduce CreateSearchConfiguration.sql to create the mb_simple search configuration
Fix script/create_test_db.sh to recreate extensions
MBS-6194: Correctly display release relationships on /release page

The code previously tried to do [% release_rels = 1 IF item.release %],
with the intention of setting release_rels to true (and never false) if
any of the items had a true 'release' attribute. However, that syntax
doesn't actually do what one would expect. Instead, I've effectively
used ||= to achieve this.
MBS-6273: Display full country/date in release events

Expands the display of a single release event to match that of a
single release label - with a single link for the country (with its
full name), and another line for the release date. If these lines are
empty, they are ommited entirely.
MBS-6360: Respond to non-UTF8 authenticated web service requests with 400

Catalyst::Plugin::Unicode::Encoding usually deals with all of this for us,
however this plugin only tries to deal with query/body parameters and URL
captures. For digest authorization, none of these are used, and instead we look
at the Authorization header. Catalyst::Plugin::Authentication::Credential::HTTP
doesn't try and do any decoding on this parameter, thus it passes the string
directly through to our Data:: layer, and finally PostgreSQL complains as it
expects everything to be valid UTF-8.

In this commit I've added a small check before we drop into Catalyst
authentication, which simply ensures that the Authorization header does form a
valid UTF-8 encoding of something. If not, the request is immediately responded
to with a 400 response.
Merge branch 'mbs-6273' into beta
Merge branch 'mbs-6360' into beta
Merge branch 'mbs-6194' into beta
Merge branch 'unaccent-extension' into beta