Refactor/rewrite

[roman01la]

I feel like the code becomes unreadable. So if anyone would like to refactor/rewrite the lib: you are welcome. Use of JavaScript ES2015 is highly appreciated, since it will make code more concise.

[havenchyk]

Let me try to rewrite.

[roman01la]

@havenchyk Thanks! Notice, we have some tests here: https://github.com/roman01la/JSONFormData/tree/master/test.

[havenchyk]

Hi, @roman01la, have you a chance to take a look?

[roman01la]

There are lots of changes. Review process is going to be slow. Don't expect this to be merged very soon :)

[havenchyk]

No problem. I just have free time and if you find anything, I can quickly fix it 😄