Implicit prop transform

[xaviergonz]

• [BREAKING CHANGE - types] Some type helpers have been renamed: ModelData -> ModelPropsData / ModelInstanceData, ModelCreationData -> ModelPropsCreationData / ModelInstanceCreationData.
• New feature: "Implicit property transforms", which are sometimes preferred over the old decorator based property transforms, collection wrappers (arrayAsSet, arrayAsMap, objectAsMap) and collection models (ArraySet, ObjectMap). Check the "Maps, Sets, Dates" section in the docs for more info.
• Added types.tuple.
• Property transforms decorators can now also be used standalone.

[coveralls]

Coverage increased (+0.1%) to 89.569% when pulling 97332ca on implicit-prop-transform into b5e6511 on master.