remove old compiler code
added new ff type: lit

this pseudo-calling convention is used for
leaving symbol addresses on stack without calling any function
new word: `2bi`
rename _stdlib -> tests, also change module name accordingly
renamed memory access primitives again:

getbyte -> getmem8
setbyte -> setmem8
get -> getmem
set -> setmem
added test-int test

checks that literal ints are correctly saved to memory
stack effects not optional anymore
fix wrong word-size literal
make vocab_roots accessible

for build system to add more paths
maybe put that into constructor arguments?
added `memcpy` and `memcpy8`
another fix for word-sized literals
debugging privatizing
fix ff generation, add MFACTOR_ROOT_VOCAB

also set vocab_root property correctly,
including user-supplied MFACTOR_SRC_DIR
and generated folder