Update login page and refactor static HTML/CSS/JS files

Links on the login page are configurable using sfconfig.yaml.

Some additional refactoring has been done to improve handling of static
files (HTML/CSS/JS). External frameworks (for example CSS Bootstrap,
JQuery, Font Awesome) should be included in the eDeploy roles and not
provided by Puppet.

Tests have been updated too, because they only checked for a 200 OK
response. This resulted in false positives and didn't detect missing
files.

Change-Id: I2a53a02737918a503e2e4534cc93170aec1f159b
Merge "Update login page and refactor static HTML/CSS/JS files"