Setting up CMake build to add xacc-config.cmake to install prefix, enabling apps building off XACC to easily integrate into cmake builds

Major repository restructure. quantum is now the quantum runtime package, moved rigetti, simple acc, and scaffold to impls dir

Setup RigettiAccelerator to look for API key in standard pyquil locations, in addition to xacc command line argument

Set up build to skip rigetti accelerator if openssl not available. Implemented better RigettiAccelerator and QuilVisitor tests. Updating fire http utils