Code can be run for nu=10^-15 or 10^-6, significant deviations for precision=1.

Also introduce check for mass conservation in prob_laplace. Currently
does not sum to 1, a factor of 2 is missing somewhere.

This reverts commit 93f115a6.

Droplet can now have different size than one and still start at zero. 
Other minor changes prior to changing units.

Frank's solution to probability problem via Laplace transform. Weirdly only works for one side right now.