[FIX] fixed proposed file extensions im emzed.io.storeCSV + cleanup
[FIX] fixed modified behaviour of openms metabo ff for mz column + cleanup
[FEATURE] logical expressions work with None values now
[FEATURE] mz align needs less peak memory now
[FEATURE] table and db version handled more liberate now.

    modifications partially hidden in commit 5240e262
[FIX] fixed broken test for emzed updater caused by commit d2cba0cb
[RELEASE] v 2.0.5
[FIX] fixed logical operations for None values
[FEATURE] more output supression for integration with showProgress=False
[FIX] added missing file test.png used in test_expressions.py
[SANDBOX] first release of feature_grouping.py