Finish parsing of files

Finish parsing of files

The load instruction now is able to go through the file and properly
parse it into a graph.
It mostly fails silently for now.
It also just deletes the graph as soon as it is constructed, because the
transfer is not yet implemented (but should be easy).
Some additional fixes were done, now valgrind does not report any leak
(except for ncurses).
A sample test was also added which should feature most of the current
capabilities. It does not test subbus access so far.