Added ignoring of data folder.
Switched from row to col vector in calculation. Dimension problem.
Fixed stupid mistake in run length.
Rewrote setting of savefilename to constructor.

Due to pointer problems in class.

Problem was that even though the string was changed it did not have that
value when used from other methods. Very weird.
Rewrote setting of savefile pointer to constructor.

Due to pointer trouble.

Weird problem as described in commit msg for SolarSystem. Wrongly
commited that file instead and don't want to rewrite the message.