Import libsodium-0.3 into the Packages Collection. Provided by csosstudy E.
in PR 47600.

	NaCl (pronounced "salt") is a new easy-to-use high-speed
	software library for network communication, encryption, decryption,
	signatures, etc.

	NaCl's goal is to provide all of the core operations needed to
	build higher-level cryptographic tools.

	libsodium is a library for network communication, encryption,
	decryption, signatures, etc.

	libsodium is a portable, cross-compilable, installable,
	packageable, API-compatible version for NaCl.

One minor change was to take the "check" target out of the post-build
state and put it into the TEST_TARGET definition.