Update rename2 (#478)

* Added pass name to debug logger

* Addresses #459. Rewords transform annotations API.

Now, any annotation not propagated by a transform is considered deleted.
A new DeletedAnnotation is added in place of it.

* Added more stylized debugging style

* WIP: make pass transform

* WIP: All tests pass, need to pull master

* Cleaned up PR

* Added rename updates to all core transforms

* Added more rename tests, and bugfixes

* Renaming tracks non-leaf subfields

E.g. given:
wire x: {a: UInt<1>, b: UInt<1>[2]}

Annotating x.b will eventually annotate x_b_0 and x_b_1

* Bugfix instance rename lowering broken

* Address review comments

* Remove check for seqTransform, UnknownForm too restrictive check