started Bayesian wind algorithm
created simple cost function
Bayesian wind considerably updated
updated method get_source_wind to return nansat object, and updated the other methods to use it accordingly
updated bayes_wind reprojection with tps=True. Same with get_source_wind-method in sar_wind
solved merge conflict
added comment regarding next step..
estimate doppler uncertainty from grid as well. Same method to be imlplemented for the NRCS