Remove underscore and clone libs and refactor code using native ES6 functions.

[danigomez]

The following files are using functions provided by underscore and clone which can be replaced by native ES6 code.

• metadata\evaluator\filter\arrayMetadataFilter.js
• metadata\evaluator\filter\defaultMetadataFilter.js
• metadata\evaluator\filter\entityMetadataFilter.js
• metadata\evaluator\metadataEvaluator.js
• metadata\model\modelParser.js
• metadata\validator\metadataValidator.js
• metadata\MetadataProvider.js

What do you think??, is there a reason to not change unsderscore to native ES6??

[andrerpena]

I don't oppose to it, I just don't find it a priority. Feel free to do it 😄

[JonatanSalas]

@andrerpena with this we reduce some dependencies, we use native es6 syntax and we could make the code for metadata management even more clear to read and understand.

[danigomez]

Great! i will start to do this!