Extract Description into separate component.

[dantleech]

All of the current desciption enhancers act upon the Payload - i.e. they don't really care about the resource.

This is not to say that enhancers can't act on the resource itself (e.g. actual files) but just that currently none of the do.

We can extract the Description stuff into a separate component that acts upon objects of any type, not just PuliResource instances.

CmfResource instances can still be supported - we just make a PuliResource enhancer which is a "proxy" to the descrition for the payload and other Puli resources (e.g. FileResource) can still be handled.

[dantleech]

If moving we should also adopt class based descriptors: #25

[dantleech]

Why was this closed?

[wouterj]

It's now distracted in a component in Psiphp, isn't it? And using that component once it's stable is mentioned in #38

[dantleech]

ok, makes sense :)