Changing projection library

* Using PROJ.4 - Cartographic Projections Library

• Coordinates changed from grid (0:nx, 0:ny) to proj-coordinates
• Grid resolution moved from class Projection to class Field
• Transformations to/from lat/lon-values must be done using Projection::convertToGeographic() and Projection::convertFromGeographic()
• Some classes still use grid-coordinates to some degree (TrajectoryPlot, FieldEdit)

• Use Field::gridResolutionX/Y, not Projection::getGridResolutionX/Y()
• Add gridResolutionX/Y to class Sat
• Remove Projection::getGridResolutionX/Y()
• Change Field::interpolate(), should use proj coordinates