remove binaries
make native.c cross-platform
fix jist script's reliance on /proc/meminfo
ignore generated files
partially fix memprof building, disable it
fix grid placement

If you placed 2 nodes in a field with X = [0, 10], the nodes would be placed at X=0 and X=5. This commit changes it to X=0 and X=10.
change build directory to 'build'