Remove FasterCSV dependency

The last remaining usage was removed in c1ee22fe
Extract public body CSV export to its own class

- SRP: Do one thing. PublicBodyCSV converts a
  collection of bodies in to a CSV formatted
  String
- Adds some parenthesis around parameters in
  PublicBodyController#list_all_csv
- Let the controller handle what records to pull
  out for the CSV export

Arguably this doesn't really need to be anything
to do with PublicBody, but it allows us to set
nice defaults.
Add PublicBodyController#list_all_csv specs

- Shouldn't include non-visible bodies
- Shouldn't include internal admin bodies
Move PublicBody domain logic from controller

Moves the magic 'site_administration' tag logic to the PublicBody
model. Easier to make the string passed to `PublicBody#has_tag?` configurable
if we want to allow this to be set per install.
Improve ActsAsXapian::Search#words_to_highlight

- Ignore stopwords
- Use Stemming
- Wrap words with regex for use in a highlighter (optional)
Add quiet_assets gem

Mutes assets pipeline log messages in development mode
Use the run-with-lockfile shell script instead of the C program

Then re-installers don't have to compile anything.
Use the EnforcedStyle key to switch from the ruby19 default to hashrockets
Merge branch 'issues/112-replace-run-with-lockfile' into rails-3-develop
Merge branch 'quiet_assets' into rails-3-develop
Add helper to highlight and excerpt by regex

Backport of https://github.com/rails/rails/pull/11793/

Contains integration tests to check that it works
as expected with ActsAsXapian.
Use regex based highlighting
Add spec for highlight_and_excerpt
Handle unhelpful stemming

Stemming returns 'bore' as the word to highlight which can't be matched
in the original phrase.

Also removes duplicates from the results
Add MAILTO option to convert_crontab task

Less manual editing for reinstallers.

Existing backwards-compatibility:

    $ bundle exec rake config_files:convert_crontab \
        DEPLOY_USER=deploy \
        VHOST_DIR=/home/vagrant/ \
        VCSPATH=alaveteli \
        SITE=alaveteli \
        CRONTAB=config/crontab-example | grep 'MAILTO='
    MAILTO=cron-alaveteli@mysociety.org

New optional MAILTO option:

     $ bundle exec rake config_files:convert_crontab \
         DEPLOY_USER=deploy \
         VHOST_DIR=/home/vagrant/ \
         VCSPATH=alaveteli \
         SITE=alaveteli
         CRONTAB=config/crontab-example \
         MAILTO=cron@example.org | grep 'MAILTO='
     MAILTO=cron@example.org
Merge branch 'convert-crontab-mailto' into rails-3-develop
Merge branch 'issues/1434-email-highlighting' into rails-3-develop
Merge branch 'issues/1415-bulk-update-public-bodies' into rails-3-develop
Strip prefix from syntax following the example on https://houndci.com/configuration
New API method for updating request state