Zyan Core Library for C

Internal library providing platform independent types, macros and a
fallback for environments without LibC.

Features:
  * Platform independent types
      - Integer types (ZyanU8, ZyanI32, ZyanUSize, ...)
      - ZyanBool (+ ZYAN_FALSE, ZYAN_TRUE)
      - ZYAN_NULL
  * Macros
      - Compiler/Platform/Architecture detection
      - Asserts and static asserts
      - Utils (ARRAY_LENGTH, FALLTHROUGH, UNUSED, ...)
  * Common types
      - ZyanBitset
      - ZyanString/ZyanStringView
  * Container types
      - ZyanVector
      - ZyanList
  * LibC abstraction (WiP)