WHATS_NEW

Version 0.3:
- Fix INSTALL.sh for system installation of Google protobuf.
- Default INSTALL.sh for x86 only.
- C++:
- - allows input std::function by const&,
- - supports type conversion function, eg. operator bool(), operator int(),
- - function API description can be any that the function can be called with,
- - template instantiation can be in a separate header file.
- Python:
- - include google protobuf support (CLIF extension library generator),
- - @async removed, the default mode is to release GIL when calling C++,
    use @do_not_release_gil to hold the GIL when not held by CLIF (it's rare),
- - use Python 3.6 for tp_ slots definition (async slots not supported),
- - allow to use virtual functions as property getters/setters,
- - make a class iterable by having a nested class __iter__,
- - experimental interface / implements statements for multiple template
    instantiations.
- Bug fixes.