Py3traits

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- Added "Motivation" section to documentation to help to discover use cases.

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- New feature: Precompiled (builtin) functions can be used with properties
- New feature: Precompiled (builtin) functions can be used as traits
- New feature: validation decorator for validating arguments by value
- New feature: Factory class for object creation
- Improving feature: type_safe and type_converted wraps functions properly
- Fixed homepage link which was pointing to Python 2 version
- Added back the missing github link in documentation
- Done a major overhaul for the core to better support adding new features
- Many other bigger or smaller improvements

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- Improving feature: setproperty does not require all property functions
- Improving feature: added name as more convenient way to name the property
- Improving example: examples/property_is_created_into_instance.py
- Changing version numbering.

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- New feature: Added setproperty convenience function
- New example: examples/property_is_created_into_instance.py
- Added documentation
- Some refactoring for testability
- Added new test utility to parametrize tests
- Added unit tests

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- First official release

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- New feature: Alternative syntax added to add_traits function
- New example: examples/composition_in_alternative_syntax.py
- New example: examples/multiple_traits_composed_into_new_class.py
- Addes unit tests