[SYMSCAE]

This PR removes customPQConfig and deprecates NoMetaStructureAdapter as mentioned in #5. GIL and performance investigations are not done, should put it in scope of further releases.

[sbillinge]

@SYMSCAE please can you make an issue for the GIL and performance investigations with enough info that we can return to it later. I will attach it to a future release. When that is done I can merge this. Please can you post the result of running tests here too as they are not running in CI yet.

[SYMSCAE]

@sbillinge I've created the issue, please see if there's more info needed. Here's the testing results and this PR needs to be merged with diffpy/diffpy.srreal#100.

libdiffpy's own cpp tests:
/home/dev/dbs/diffpy.srreal/build/nopq/libdiffpy/build/develop-x86_64/tests/alltests Running cxxtest tests (175 tests)...............................................................................................................................................................................OK! scons: done building targets.

srreal's tests:
429 passed, 423 warnings in 1.70s