ENH: adjust tokenizing

added 8 commits

• 2988e247...739c1c1d - 3 commits from branch develop
• efd1ac4b - ENH: adjust token in preparation for separate expression tokenization
• 44a243a9 - ENH: improve stream handling of expansions (#2095 (closed))
• c9fda67b - ENH: refactor function arg splitting -> stringOps::splitFunctionArgs
• 2dbabb24 - ENH: namedDictionary for managing keyword/dictionary combinations
• ec81436c - TUT: generalize (parameterize) blockMeshDict for half-cylinder geometries

Compare with previous version

Adjusted error handling and additional comments as suggested by @andy

assigned to @Sergio and unassigned @andy

mentioned in commit edbee862

merged