Ignore .o-files in graphics assignment 6.

TODO: implement the other switch cases in gup_handler().

Also added ignore list.

This commit also includes the beginning of the LaTeX document
containing the paper's content.

Graphics include the following assignments:
 - ass1
 - ass2
 - ass4
 - ass6

Operating systems include the following assignments:
 - ass1
 - ass2

This commit includes assignment 2 and the syllabus of the
subject Algorithm & Complexity of the University of Amsterdam.