clarified tool setup for GHC / OCaml: discontinued "isabelle ghc", "isabelle ocaml", "isabelle ocamlc" to avoid confusion with traditional settings variables for executables (these are still required in existing applications, notably in session options [condition = ISABELLE_GHC] etc. and codegen setup;
src/Pure
src/FOL
src/HOL
src/ZF
src/CCL
src/CTT
src/Cube
src/FOLP
src/LCF
src/Sequents
src/Doc
src/Tools