Port the rest of the development, and move files around.

_CoqProject

theories/lang/adequacy.v

theories/lang/derived.v

theories/lang/heap.v

theories/lang/lang.v

theories/lang/lifting.v

theories/lang/memcpy.v

theories/lang/notation.v

theories/lang/proofmode.v

theories/lang/races.v

theories/lang/tactics.v

theories/lang/wp_tactics.v

theories/lft_contexts.v

theories/lifetime/definitions.v

theories/lifetime/derived.v

theories/typing/perm.v

theories/typing/perm_incl.v

theories/typing/type.v

theories/typing/type_incl.v

theories/typing/typing.v