fix xhrs for file URLs
support reading binary data in the shell/node
use a separate memory initialization file
ensure runtime initialized when dependencies have arrived, including the memory initializer
refactor preRun additions
load memory initializer immediately
assert on callMain happening when no dependencies left
debug printout
do not copy mem file when already in all places
fix test_optimize_normally
add test coverage for not using a memory initialization file
fix test_emcc