bliss: Fix compilation warning with certain GCC versions

Theoretically, n could be zero and these variables are then used
uninitialized.  Older GCC versions warn about this and on Travis where we
compile with -Werror this causes the tests to fail.
bliss: Fix monolithic build

This requires moving test files so that the Makefile for the tests can be
included after building libstrongswan, which requires the plugin when
building monolithically.  Due to this a static helper library is required
as directly referring to object files (or source files) is not possible.

It's also necessary to avoid any link-time dependency on libstrongswan in
bliss_huffman, to avoid circular dependencies (bliss_huffman -> libstrongswan
-> bliss -> bliss_huffman).
Include design parameters in generated Huffman code files
Use Huffman code in BLISS signature
Use bitspender->get_bytes() method in ntru_trits
Updated BLISS scenario keys and certificates to new format
Version bump to 5.2.2rc1