* llama2.c: direct gguf output (WIP)
* Simplify vector building logic
* llama2.c gguf conversion: fix token types in converter
* llama2.c: support copying vocab from a llama gguf model file
* llama2.c: update default path for vocab model + readme
* llama2.c: use defines for gguf keys
* llama2.c: escape whitespaces w/ U+2581 in vocab converter the llama.cpp way
* llama2.c converter: cleanups + take n_ff from config