Now that runner is invoked via the rails command and not directly from the script directory, it's more important to cd to the app directory in order to pick up the bundler gemfile. Fixes #964.
Merge branch 'fix-cron-bundler-gemfile' into rails-3-develop
Merge branch 'rails-3-develop' of ssh://git.mysociety.org/data/git/public/alaveteli into rails-3-develop