Objective of issue: Virtual ports need to be supported between RefPorts and VarPorts also

Lava version:

• 0.3.0 (feature release)
• 0.2.1 (bug fixes)
• 0.2.0 (current version)
• 0.1.2

I'm submitting a ...

• bug report
• feature request
• documentation request

Current behavior:

• When trying to create a virtual port on a RefPort, an exception is raised.

Expected behavior:

• No exception is raised but the virtual port works.

Steps to reproduce:

Related code:

insert short code snippets here

Other information:

insert the output from lava debug here