Version beta7

Important security fixes:
- Added missing HTML encoding to postal address of member
- Link to discussion URL only if it starts with http(s)://

Other bugfixes:
- Fixed wrong display of 2nd level delegating voters for an initiative
- Do not display invited initiators as initiators while voting
- Added missing translation

New features:
- Public message of the day
- Both direct and indirect supporter count is shown in tab heads
- Support shown in initiative lists

Language chooser at the login page has been added (again)