This is a service that basically describes the properties passed to
loadComponentFromURL and possibly other load/save related APIs.  As
some properties get deprecated (some already have), new ones added as
the loading processs gets re-worked (including the type detection
process), we need the flexibility to change its property set.

Since all properties described here are optional, leaving it published
would make little sense.

Change-Id: I59384e62c7b6ab5c599141c8fc73a37c8bfe56e7