Add namespaces for components / pages

[eWert-Online]

There should be some kind of namespace option, for component libraries to be viable in pinc.
Currently without namespaces, it would still be possible, as you could just prefix your component with a namespace (Pinc_Button, PincButton, ...).

It could also be an option to allow some more characters in definition identifiers (:, ., ...).

A possible syntax for namespaces could be:

component Button(namespace: "Pinc") {
  // ...
}

component Something {
  <div>
    <Pinc.Button />
  </div>
}