Request: create operator for coordinate conversion between WGS84 and Mercator (a la RS2LatLong)

[jipclaassens]

Maarten has a method in mind which is much much faster than Proj4.

[cjacobscrisioni]

This would be very useful for a bunch of applications at JRC

Edit: especially if this allows us to circumvene the issue with inverted x,y values in WGS84 that prevents direct casting of arcs and polys from WGS84 to anything else