Add release notes for 0.6.9
Merge branch 'hotfix/0.6.8.3' into release/0.6.9

Conflicts:
    Gemfile.lock
    locale/ar/app.po
    locale/cs/app.po
    locale/cy/app.po
    locale/en_IE/app.po
    locale/es/app.po
    locale/pt_BR/app.po
Latest translations pulled from Transifex to fix inadvertantly committed unmerged conflicted files.
Bump Alaveteli release number.
Latest translations pulled from Transifex.
Update Gemfile to use a security patched copy of rails from the mySociety git repo
Add updated Gemfile.lock after running bundle install.
Add note on Rails security upgrades to change file.
Try just specifying that rails should come from git, to avoid deprecation warnings about "require 'actionmailer'" rather than "require 'action_mailer'" etc.
Merge branch 'release/0.6.9' into develop

Conflicts:
    Gemfile.lock
    locale/cy/app.po