Starting to port to new Lem.
Getting the semantics ported to new Lem

They build now in new Lem and generate HOL, but not good HOL yet.
Missing from previous commit
More progress
A few more tweaks
More tweaks
More progress.
Almost works.
The semantics builds with latest Lem
The semantics and metatheory directories work
Further updating for new Lem
Fix some types in response to some Lem bug fixes
Merge branch 'master' into new-lem
Toward getting the translator working with new Lem
The translator builds now.
Bytecode now builds with new Lem
Started to work on updating the compiler.
Slight progress
The compiler builds in Lem, but the HOL doesn't compile
The compiler builds now.