Looked at possibilities to make the code a bit cleaner and easier to do some things. Got stuck (or obsessed may be more accurate) on realloc'ing the program space.

Missed a day :(

Did some cleanups and additions to a stack based VM I wrote a while back in C. One cleanup was to pull the frequent underflow checks into a C macro. I added some VM stack ops dealing with stack manipulation that corelate directly to the Forth words: ?DUP, OVER, TUCK, & NIP. I also simplified my implementation of ROT & -ROT to just do the top three items instead of taking a top item and doing an arbitrary rotate.

Overall: 7 files changed, 124 insertions(+), 137 deletions(-)