Revert "Link against openssl, add crypto.c/.h"

This reverts commit e04401ae6156d5127f4cf8e2671e02f5db010154.
Revert "Revert "Added building nacl crypto, early crypto code""

This reverts commit 29517056d4b8e8f61edffc02152f18404434d227.
Revert "Revert "More crypto...""

This reverts commit 61307cb6e9e1adf31a64cd7cc49d4b7bb9ea8e1d.
Revert "Revert "Generate node IDs from public keys now""

This reverts commit 7c02b7670954a1d0b9fd653f5fe03443a8abad89.
Revert "Revert "Fixes for node IDs, filtering out multicast packets, etc""

This reverts commit 709388bc149d83a97950b6f5c2372493aca634e5.