rename Hashweak to Weakhtbl

Makefile.in

src/core/decl.ml

src/core/decl.mli

src/core/env.ml

src/core/env.mli

src/core/ident.ml

src/core/ident.mli

src/core/task.ml

src/core/task.mli

src/core/term.mli

src/core/trans.ml

src/core/ty.ml

src/core/ty.mli

src/util/util.ml

src/util/util.mli

src/util/weakhtbl.ml

src/util/weakhtbl.mli

src/whyml/mlw_expr.mli

src/whyml/mlw_ty.ml

src/whyml/mlw_ty.mli