Revert "Fixes for node IDs, filtering out multicast packets, etc"

This reverts commit 2d07c86591c1d756f2699df229f2a394f2d2ccc3.
Revert "Generate node IDs from public keys now"

This reverts commit cd4bb638dad063f5a17cacc513baa9cbab0009c0.
Revert "More crypto..."

This reverts commit 0430b44343e2365b2bc0310943350079a6d0d245.
Revert "Added building nacl crypto, early crypto code"

This reverts commit 640899a749811c422d1a5d67a56de7ebf3b141a2.