Preprocessor update

— fix LaTeX compilation error with some expressions (#263)
— fix handling of some special characters in LaTeX
— add “xls_sheet” and “xls_range” to “calib_smoother” (#1695)
— license file update

preprocessor @ 1d31e00b

-Subproject commit f63449c5a6205e1a040b91cf09c2f1529ab84390
+Subproject commit 1d31e00b818708a9f895e0b20e43cc8a83acc2ce