[MERGE] Transport.local_abspath should raise NotLocalURL rather than TransportNotPossible.

[Martin Pool]

Martin Pool has voted +1.
Status is now: Approved
Comment:
I think I added a test for this too, you might want to cherrypick it as 
well?

For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C1176177809.18680.30.camel%40localhost.localdomain%3E