Release 2.0.0

• Switched to using faster non-cryptographic hash functions and a faster insertion method.
• Created .NET Standard wrappers for the public API.
• Kuku is not a CMake project (with a top-level CMake file).
• Kuku now allows any size hash table -- not just a power of two.
  Note the change in the constructor of the KukuTable class that now accepts the table size directly, and not its base-2 logarithm.
• Changed name KukuDotNet to KukuNet.
• Added NuGet package.