Refactoring: Noelle is a single shared library and has a menuconfig

Added make menuconfig
src/core compiles down to a single shared library (.so)
Each tools still compiles to a separate shared library
Scripts generate a call stack when something fails
Noelle can be used with FetchContent and ExternalProject (see section "NOELLE as an external project" in README.md)
New tool noelle-scc-print
Show calls to opt prefixing with DEBUG=1. E.g. DEBUG=1 noelle-privatizer args
General update of README.md
Improved noelle-config
src/core and src/tools contain C++ code only
CodeSize is now a tool

arcana-lab / noelle