Shear calibration

Added functionality to perform a calibration on the shear. Shear can now be synthesised at the turbine location using a correlation derived during the site calibration period. This can be performed using the same calibration methods as the wind speeds. It is done on a directional basis, using the same bins as the wind speed calibration. Data are taken from post wind speed calibration filtering.
Of course this option does not have to be used.

Changes affecting GUI performance have not been fully tested.

Other changes have been made to reporting and typos here and there.