Whitespace.
Fix routing of group#all_geometries, and give permission to guests to use it.

Perhaps this was the problem Shaun was running into - it certainly gives the same
error message. If I'm wrong, then we can get a stack trace blaming the indicated
line of code.
Add auto_link to description, and simple_format when shown on the webpage.
Make string translatable.
Refactor logic around showing group joining.

As previously written, if you weren't logged in, you were assumed
to be in the group!
Based on #273 show to logged out users.
Move pending string in translations, and adjust tests.
Fix faulty should_not have_content - always hard to spot these.
Remove new group button.

The permissions were broken, and it's quite an instrusive button for something
that people are rarely going to do.

Replaced with (translatable) text at the bottom of the page.
Link to the groups list from the groups box on the front page.