Make sky-pfi coordinate transformation more consistent with AG

Kawanomoto-san developed the coefficients for the fiber focal plane using the same function as that used for the AG focal planes. Use this function for sky-pfi coordinate transformation. Also, the study using AG reveals that corrections of proper motion and equinox etc. is slightly different b/w Az-El and InR (in the telescope), so the correction is better to handle in pfs_utils.  I talked to Martin this point, and he agreed to call sky-pfi transformation using J2000.0 catalogue. Also he pointed out that unnecessary arguments needs to be deleted.