Enable -std= for cmake builds, fix warnings (ggml-org#598)

Add AVX acceleration (ggml-org#617)

* ggml : add AVX quantize_row_q4_0()

* ggml : add AVX ggml_vec_dot_q4_0()

* ggml : refactor AVX part of ggml_vec_dot_q4_0()

ggml-org#617 (comment)

Optimize AVX2 ggml_vec_dot_q4_0 (ggml-org#642)

Introduce GGML migration tool for new file format

If you deleted your old Meta LLaMA .pth files, then the
migrate-ggml-2023-03-30-pr613.py script will allow you to convert your
old ggml files into the new mmap()'able format.

See ggml-org#613

Fix GGML_F32Cx8_STORE in AVX without F16C path (ggml-org#619)

Remove unused variable (ggml-org#607)

* It seems some new warning were added recently that exposed this.  I wrote the code that included this unused variable originally and it is indeed not needed.

ggml : fix NEON signs (close ggml-org#620, ggml-org#622)

cmake : properly invoke CTest (ggml-org#629)

make : fix darwin f16c flags check (ggml-org#615)

...there was no check.  ported upstream from zanussbaum#2 (I dont see any clean path for upstream patches)

ggml : add ARM_NEON quantize_row_q4_1()