Schema.org type serialization invalid when http and https are mixed

[rvanlaak]

issue #24 does describe the argumentation the semantics of on namespaces being different. This is something we can work around as the library's implementation is flexible enough for that.

A consequence is that calling item->toObject will lead to an invalid type:

An IRI as http://schema.org/https://schema.org/WebPage can be seen as invalid.

What about adding several helpers for sanitizing / handling http & https on the profile equally?

Schema.org redirects http to https since a while, so both can be seen as identical. That would solve the following inconsistency: