Remove malformed?/1 in favor of well_formed?/1

[Cantido]

Is your feature request related to a problem? Please describe.
Since the malformed?/1 callback is a negative question, we cannot return values, like the result of a successful parse.

Describe the solution you'd like
Replace it with a well_formed?/1 decision.

Describe alternatives you've considered
Allowing some way to return a negative while also returning data. Sounds gross to me.

Additional context
Since this will remove a decision, this needs to be a major version bump.

[Cantido]

well_formed?/1 is now in master and malformed?/1 is deprecated. I'm going to leave this open until malformed?/1 is removed in 2.0.0.

[Cantido]

Fixed in version 1.4