Fixed world coordinates in PSF-fitting.

Fixed error ellipse measurements in PSF-fitting (but works only for PSF_NMAX=1 currently).
Simplified PSF parameter handling (removed PSFDISPLAY_TYPE configuration option).
Simplified triggering of local north axis computation.
Allowed model axis ratios to exceed 1 to facilitate convergence.
Fixed alignment bug for symmetric models.
Restricted maximum allowed range for model coordinates.
Pushed version number to 2.10.0.