Scorep

This release fixes 144 and makes the instrumentation consistent again.

Rolling back to Distutils as Setuptools introduced a bug ( 142 ).

What's Changed
* The python Instrumenters does now also apply try_region_[begin|end] and are therefore faster
* The backend requires now c++17 as `string_view` is used a lot to avoid string copies (therefore 4.0.0)
* Implement cTrace and cProfile for python 2.7
* Update ci
* move to setuptools

**Full Changelog**: https://github.com/score-p/scorep_binding_python/compare/v3.4.0...v4.0.0

* Instrumenter file, to allow user and selective instrumentation without changing any files
* Some updates to the Benchmarks
* Remove Onlne Access (OA) Interface
* The OA-Interface is no longer enabled per default in Score-P and deprecated
* Add decorators for selective instrumentation
* Check for access to TMP dir, as some HPC-Systems might forbid executing from `/tmp` in some cases.
* Add `force_finalize` to finalise a trace
* Please note: adding events to a finalised trace is unsupported
* Add `reregister_exit_handler` in case Score-P's exit handlers have been overwritten
* Performance optimisations
* Check if a region is already known before asking for any strings
* cTrace/cProfile only

* Fix an exception that might occur during the shutdown of a process.

We have only seen this in some multiprocessing use cases, so no need to worry.

We choose to enable the cProfile instrumenter as the default instrumenter when available, e.g. currently only using CPython 3.

However, during the change, we decided to modify the build and initialisation process a bit. As a result, we can now support PyPy using the traditional Python instrumenters. With minor modifications to `scorep/instrumenter.py:has_c_instrumenter()`, it might be possible to extend the support to other Python instrumenters as well, but that is not supported.