NC: I-42, NC 540 extension signed

[jlam]

North Carolina's Interstate 42 bypasses and the NC 540 Triangle Expy extension should be added. They're pretty thoroughly signed.

[Markkos1992]

We already have other threads on these subjects.

I-42:  https://forum.travelmapping.net/index.php?topic=6422.0
NC 540:  https://forum.travelmapping.net/index.php?topic=5959.0