Refactoring: Single CMake project

core and tools are now a single cmake project
tests and examples have been adaped , but not restructured to be a single project (that's low priority)
external have been adapted, but not restructured
Full recompilation is triggered only after make clean
Finally a single compile_commands.json automatically linked by cmake in the root dir (clangd in happy)
Adding a pass now straightforward (add one cmake line)
Can run make from the top directory without worrying about project dependencies
Building core and tools is 2.6x faster according to my tests
make JOBS=<N> really scales (but not for SVF or SCAF, no biggie, we only build them once)
noelle-config has now --git-commit and --git-origin (and they are automatically generated)
Change VERSION to change what noelle-config --version displays
src/<core|tools>/<module>/include/**.hpp are considered public headers, and as such, they will be installed
Pull request #124 already integrated
Cmake optional -DNOELLE_ENABLE_REPL=On
Installing to a different location than ./install doesn't work because external has to be ported under cmake as well

arcana-lab / noelle