Streamline templates, more DRY

Use Unified function to emit <link> tags for css loading, obey "Don't Repeat Yourself" ;-)

(Next step might by to combine this with the emit <script> function (even more DRY?) AND move all this to a better place?)

Signed-off-by: Michael Letzgus <michaelletzgus@users.noreply.github.com>