In process of getting adaptive dm to work.

* Fixed loop, is now while so that will always reach center of star
  unless something is zero.
* saveEvery is now deprecated - now use new var massPile to count how
  much mass has been passed and every time a change of 0.0001 of the
  starting mass is reached, a point is written to the datafile.
  This will be conventient for huge simulations.
* Added an upper dm limit, so that if the proposed dm is bigger than
  this, a limit is set. Problem now is that this always happens.

TODO: There is obviously something wrong in the calculation of the new
dm, so that it is set to be way huge. Check this, if the adaptive dm
starts working. The program will be better.

TODO: Remove all traces of the saveEvery var, it is no longer necessary.