Be more consistent about free (shallow) vs drop (deep)
rename lv-partially-initialized and lv-fully-initialized to shallow/deep resp
add lv-dropped-if-necessary
add free/drop and some tests for them
Add free-pointer, free-variables, and free to reduction semantics
Change reduction semantics not to *drop* variables but just *free* them,, and not to ignore void during drop
Convert to not zero memory upon use, remove copy form
add bk-ok and some basic tests
add fn-ok and prog-ok
comment out test for fn-ok which does not work yet