Inline Rename performs a rename operation on an initial solution to produce a new solution with all references renamed, conflicts resolved, etc. This new solution may contain linked documents with un-merged (and potentially conflicting) contents. This change applies this linked file merging step to present properly merged changes and rename tags.

If a file on disk D.cs is linked in two Projects P1 and P2, then there are two documents D1 and D2, with their contents being equal. When a symbol is renamed, we have a new solution with documents D1' and D2'. We calculate the text changes between D1 & D1' (C1), and D2 & D2' (C2), and merge these changes C1 and C2 into a final set of changes which produces the new merged Documents, D1m and D2m, with their contents being equal. Each document D1' and D2' knows its rename information, such as the location of definitions, references, and resolved/unresolved conflicts. This information is mapped to D1m/D2m for display in the editor by tracking spans from D1' to D1m, and D2' to D2m. The final locations of these tracking spans is their location in the merged buffer contents. (changeset 1389424)