Support Jacobian/Factors in kp

[busstoptaktik]

With #54 merged (5eab7f2), it is now possible to support geometrical factors in kp.

It should work much like the -S and -SV options in proj:

$ echo 12 55 | proj -S +proj=utm +zone=32
691875.63       6098907.83      <1.00005 1.00005 1.0001 1.20736e-06 1.00005 1.00005>

$ echo 12 55 | proj -SV +proj=utm +zone=32
Longitude: 12dE [ 12 ]
Latitude:  55dN [ 55 ]
Easting (x):   691875.63
Northing (y):  6098907.83
Meridian scale (h) : 1.00005168  ( 0.005168 % error )
Parallel scale (k) : 1.00005168  ( 0.005168 % error )
Areal scale (s):     1.00010336  ( 0.01034 % error )
Angular distortion (w): 0.000
Meridian/Parallel angle: 90.00000
Convergence : 2d27'29.52" [ 2.45819987 ]
Max-min (Tissot axis a-b) scale error: 1.00005 1.00005

(also see #46)