Improve blue wavelength solutions

Roman Gerasimov reports that the wavelength solutions at the blue end of the blue arm are generally poor, showing a wavelength offset from stellar models fit using the MR arm.

The attached spectrum (10092x25769810054.dat) provides an example stellar spectrum we can use to test the wavelength solution for catId=10092 objId=25769810054.

Input visits: 122783, 122784, 122785, 122786, 122793, 122794, 122795, 122796, 122798, 122799, 122800, 122801, 122803, 122804, 122805, 122806, 122807, 122808, 122949, 122950, 122951, 122954, 122956, 122957, 122958, 122959, 122961, 122962, 122963, 122964, 123064, 123066, 123067, 123069, 123070, 123071, 123072, 123074, 123075, 123076, 123077, 123079, 123080, 123172, 123173, 123174, 123175, 123177, 123178, 123179, 123180, 123182, 123183, 123184, 123185, 123187, 123188, 123189, 123190, 123192, 123193, 123194, 123195, 123200, 123201, 123291, 123292, 123293, 123294, 123296, 123297, 123298, 123299, 123301, 123302, 123303, 123304, 123306, 123308, 123309, 123311, 123312, 123313, 123314, 123316, 123317, 123396, 123397, 123398, 123399, 123401, 123402, 123403, 123404, 123406, 123407, 123408, 123409, 123411, 123412, 123416, 123417, 123418, 123419, 123423, 123424, 123426, 123427, 123428, 123429, 123526, 123527, 123528, 123529, 123531, 123532, 123533, 123534, 123536, 123537, 123538, 123539, 123540, 123541