Grid interpolation and spinup-time

This release focused on better usage of the driving meteorological input data. By using the grid-interpolation routines of the fimex library, SNAP can now be run in a horizontal grid different from the meteorological driver. The grid-projections which are automatically recognized include now also polar stereographic as well as rotated latitude-longitude grids. In addition is it now possible to specify the spinup time for the preferred best meteorological dataset.

Smaller changes in this release include addition of particle split to improve statistics of long-distance model runs. A timer was added to the log-files to better compare run times. Some memory leaks have been found and removed and the legacy and no longer maintained milib integration has been removed.