Name changes to scopes and objects need more careful handling

[bgribble]

The global/local send/receive issues in #224 brought to light that sometimes changing an object's name can have significant side-effects. This ticket is to review and implement any changes needed to allow

• scopes
• objects
• patches

to change names, particularly paying attention to the interaction with invisible [bus] objects and send/receive vias.

[bgribble]

A particular problem case: let's say you want to create a send-via to a specific object which will have a special name. If you accidentally create the via first, it will create a [bus] with the name that you want to use; then, trying to rename an object to the desired name will fail. For example:

v foo RET 
p print RET
! @rename('foo') RET  

leaves the [print] named foo_002 and the via connected to nothing. But creating in the opposite order, so that the print is named first, works as expected.

This is pretty understandable from a runtime order-of-operations perspective, but it is surprising if you expect the patch to be declarative.