Move to single point of definition for the template parts by using
include instead of the inline content

The template allows to quicly start a presentation
that makes use of the include directive to get the header and footer
relevant to the NTNU theme

* remove leftover text from a git conflict
* change the presentation to include the header and footer

Supprorting material with administrative issues slides

Supporting slides for the git demo lecture

Presentations including the footer should set the LECTURE_TOPIC
LECTURE_NO attributes so that the proper information is displayed
in the footer area of the presentation.

Example:
:LECTURE_TOPIC: Git demo
:LECTURE_NO: 4th lecture

slides
Header and footer includes have been added

started slides for 2nd lecture

same thing done for lectures

with the university name on the right