Bugfixes

See merge request !79

firefox bugs with the flip animation and flashcards aren't priority in voting

CSV delimiter

See merge request !78

Available options:
* Value delimiter
* Excel format (additional header)

A new Grunt 'fonts' task has been implemented which downloads Google
Fonts.

* Run Maven in batch mode
* Cache Maven dependencies

GitLab can handle this w/o scripting by now.

Refactored deployment script to allow flexible deployments for different
hosts and environments.

change guest login method from GET to POST

See merge request !75