WAMR-09-08-2020

Implement post-MVP multi-value feature
Implement post-MVP threads, shared-memory and atomics features
Implement lib-pthread support
Implement post-MVP wasm-c-api feature
Implement WASI and lib-pthread for Linux SGX platform
Enable Windows platform support
Refactor app heap and boundary check
Update AOT current version from 1 to 2
Implement two new APIs for wasm function call