allow to login with email instead of nick as well + tests
start of making nickname optional
fix typo breaking invitation
make search work without nickname usage
more user display changes
user display changes in model and mailer
small model change
make user creation possible again
show user name with use_nick is false
beautify map invocations of users
fallback for when nick is nil
fix new user form
Merge branch 'master' into allow-no-nickname

Conflicts:
	app/views/foodcoop/users/_users.html.haml
clearer login field name
make authentication methods more readable (thanks @fsmanuel)
add unit tests for shared database synchronisation
do not error when calling shared_article on non-shared article
fix rspec warning
Merge pull request #202 from foodcoops/update-spec

Add tests for shared database
use dynamic conditional in validation, to enable different foodcoops having different use_nick configuration values