new gitignore for ignoring everything but D source files and markdown files.
Add 1K/2K/4K/8K data files from Sedgewick&Wayne's website. I'm guessing there's no license needed on a file full of integers.
Allow text files in gitignore
in stack, fix the references to addBeginning/deleteBeginning
use replace/split to parse input in dijkstra_arith
Add a constructor for LLstack. We need to initialize the linked list before we use it, dummy
remove test code
add brute-force implementation of threesum along with some code for pulling in ints from files