Renamed 'Local_context' to 'Context'

The module 'Local_context' stores all contexts, the global and all
local contexts. Therefore it represents the *context*.

	renamed:    ocaml/local_context.ml -> ocaml/context.ml
	renamed:    ocaml/local_context.mli -> ocaml/context.mli
	modified:   ocaml/eiffelc.ml
	modified:   ocaml/prover.ml
	modified:   ocaml/prover.mli
	modified:   ocaml/typer.ml
Removed the 'new_prover' because it is overcome by events

	deleted:    ocaml/new_prover.ml