got rid of another taboo that appears to make no difference in practice (and that slows down the relevance filter)
src/Tools/Code
src/Tools/jEdit
src/Tools/Graphview
src/Tools/WWW_Find
src/HOL/Mirabelle
src/HOL/Mutabelle
src/HOL/Library/Sum_of_Squares
src/HOL/Tools
src/HOL/Tools/ATP
src/HOL/Tools/Sledgehammer/MaSh
src/HOL/Tools/SMT
src/HOL/TPTP