Modify INTEGER! multiplication to not use division for overflow detection.
Modify INTEGER! addition and subtraction to not use undefined arithmetic.
Modify integer comparison to not use undefined arithmetic.
Fix bug#2054
Do not use MAX_NEG_INT in t_integer.c (problematic name).
Amend a comment referring to reb-config.h
Merge pull request #145 from ladislav/mul64

Modify INTEGER! multiplication to not use division for overflow detection.