Require Flask-Babel and transifex-client
Move frontend files to website/frontend and use Flask Blueprint

Inspired by CritiqueBrainz structure
Move config to website/, provide a default and allow overriding
Add a simple cache to the application
Use caching instead of loading changelog on all requests
Rework plugins stuff

- use memory caching for plugins json file
- drop very badly implemented (and useless?) download count
- simplify and fix code to work with blueprints
Move changelog-specific jinja utility functions to changelog view
Initial support for multiple language support

- add selector for language in footer
- use fabric (fab -l)
- transifex support is ready (but project isn't exist yet on transifex)
Mark for i18n
Go further to test translation process

- fr.po added as example/test until all strings are marked
- found a way to handle urls
- minor changes in templates (blueprints and url_for())
Add an 'expand' filter to jinja2

- update templates
- update translations

More or less the same thing as https://github.com/metabrainz/musicbrainz-server/blob/master/lib/MusicBrainz/Server/Translation.pm#L194
Thanks to Nikki + bitmap for the pointer
More blueprint/i18n changes
More i18n
More i18n
Minor fixes on download page
More i18n
fabfile: add `plugins_generate` command
Update install procedure
Development server is now listening on 127.0.0.1 by default

It is safer to have it not listening on all interfaces by default.
Modify documentation accordingly.
Minor INSTALL.md change