reorganise some more bootstrap lemmas

- Move everything about the translator's refinement invariants into
  translator/repl.
- add new evaluate_repl_decsTheory, to hold theorems about the semantics
  of the REPL module and of making the call to repl step.
- Update READMEs.
- move FUNION_FUPDATE_1 to HOL's finite map compset.
fix proof broken by change to finite map compset