Prophy

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- prophyc: python3 bug in C++ frontend fixed (libclang invocation contained unicode strings)

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- prophy: decoding exceptions contain information about decoded type
- prophyc: sack parser processes isar-using hpp files with array members
- prophyc: bugfix - option parsing doesn't throws exception out of interpreter

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- prophyc: can be invoked directly from python code
- prophyc: sack parser can implicity include definitionos from isar files
- prophyc: enums also included in model even if not used in structures
- prophy: forgiving misspelling in sizer name of ext sized array

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- prophyc: sack parser properly handles typedef in namespace
- prophyc: sack parser prefers clangs up to 3.5, they don't ship with builtin headers (e.g. "stddef.h")

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- prophy: copy_from works for optional fields
- prophyc: sack parser adapted to clang 391

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- prophyc: clang python plugin vendored, libclang.so found more easily
- prophyc: isar parser: negative enum values treated as large unsigned numbers, like in sack
- prophyc: isar parser: optional struct member is optional according to attribute value, not presence
- prophy_cpp: packed attribute used in --cpp_out structs declarations
- prophy: python3 prints structs with bytes fields correctly
- housekeeping:
- travis and tox improved
- coverage added
- flake8-compliant