Preprocessor update

— new command “evaluate_planner_objective” (#1678)
— some new symbolic simplification rules
— various fixes to “epilogue” block (preprocessor#36)

preprocessor @ c1b8cdf8

-Subproject commit 5430bb4bc63e254af23bd0006f25aef33f3cbdcf
+Subproject commit c1b8cdf811b94ed725111a8b013ec5fd24849aac