Version 0.5.0

• API changes:
  • Support for cartesian x/y coordinates (instead of just lat/lon)
  • A bilinear interpolator that works on all grid rotations
  • Easy cross-validation setup for optimal interpolation
  • Functions for computing distance to nearest points on grid
  • Functions for computing number of nearby points on grid
  • Function for computing neighbourhood quantiles with spatially varying quantiles
  • Function for gridding observations
  • Function for filling in missing values
  • Experimental method for optimizing a metric (metric_optimizer_curve)