Fixes #5076

- Introduce instructional text when the dashboard is first shown (or when newName = originalName). This should help users who are used to the pre-VS2015 modal dialog learn to edit the identifier inline in the editor. If we at some point add a way to launch Inline Rename with a new name already specified, we'll need to be a bit more careful about how to both show that new name *and* the instructional text.

- Show the newName as the user types it

- Rearranging the info in the window to flow a bit better:
    - Heading (rename from x to y, or show getting started instructions)
    - Settings
    - Summary (# locations to be updated and any conflict info).

- Slightly changed the reference count text from "found 1 reference in 1 file" (which made sense in large solutions where you saw "Searching..." for a while, which then got replaced with this text) to a more standalone version of "Rename will update 1 reference in 1 file."