Adding missing features of CMakeLists.txt & Refactoring (#131)

* Functionality addition CMakeLists.txt

Refactoring:
1. Simplify more options that are negation of negation.
LLAMA_NO_ACCELERATE -> LLAMA_ACCELERATE
2. Changed to an optional expression instead of forcing to enable AVX2 in MSVC.
3. Make CMAKE_CXX_STANDARD, which is different from Makefile, the same.
4. Use add_compile_options instead of adding options to CMAKE_C_FLAGS.
5. Make utils use target_link_libraries instead of directly referencing code.

Added features:
1. Added some options.
LLAMA_STATIC_LINK,LLAMA_NATIVE,LLAMA_LTO,LLAMA_GPROF,LLAMA_OPENBLAS

* Fix Accelerate link in CMake

* Windows build Fix

* C++11 to C++17

* Reflects C/C++ standard individually

* Change the version to 3.12

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Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>