CMake and build process improvements, 4 new targets, minor fix to avoid unwanted compiler optimisations.

Added

• Add static build targets ascon128hash, ascon128ahash, ascon80pqhash
  which compile to static libraries with the indicated AEAD cipher and
  the Ascon-Hash/Xof functions. Useful to avoid setting manual compile targets
  when only one cipher and the hash functions are needed.
• Add test runner which tests the shared library build target testasconshared
  to check that everything works also with dynamic linking.

Fixed

• Prefer memset_s when available to clear the context, as memset may be
  optimised out by the compiler, while memset_s is guaranteed to always
  execute.
• Improved CMakeLists.txt:
  • Bump minimum CMake version to 3.9 to use the
    INTERPROCEDURAL_OPTIMISATION property (aka Link time optimisation)
    on just the targets that need it.
  • Remove -flto flag, it may cause compiling issues in some cases (breaking
    the Travis CI build, for one), prefer CMake's abstraction as per point
    above.
  • List explicit include directories for each target.
  • Add explicit dependencies to each target that has some.
• Improved Travis CI:
  • Enable parallel make-all.
  • Install MSYS2 and use GCC on Windows to compile properly.