Determine if initial subject uri harvest is needed for path assertion

[cedricdcc]

Before the scenario tests were writen the initial subject that the SubjPropPathAssertion must start from was not harvested right away.
This resulted in the behaviour of travharv that it would try and get all the assertion paths but for the first one It would always go back to the max deph of an assertion path and then harvest the uri.

This lead to missing info for the first property path assertion.

I have included the harvesting of the first subject by default to counter this.

But from a philosophical view this is wrong since I must always assume with travharv that the knowledge I have up until the point of dereferencing a URI is what I have to work with , so if that knowledge is none, it should work like before.