Add a shortcut for templates/sub-parts containg no includes to skip parsing

[AndreasKl]

As an optimization it would be nice if a template does not contain any includes, can indicate that the content can be passed straight into the result with no parsing at all (ignoring the the content tag)
Also includes that have no need for a "content"-tags and does not need any parsing could indicate that. This could be useful for json objects for analytics.
<c-include path="..." mode="parse/**pipe**"></c-include>

[thovid]

So, a content fragment could decide to just return the <div>...</div> with the content, without head etc?

[thovid]

Btw, html pages can skip parsing by being routed to via a proxy route ;-)

[AndreasKl]

@thovid at least an include is always processed which is potentially not always needed. I could think of a service that renders a script tag with a few javascript variables.