[R-Model, R-Refactoring] Fixed "rename in workspace" refactoring (element
was renamed twice).

(reported by Vlad Sharanhovich)

Signed-off-by: Stephan Wahlbrink <sw@wahlbrink.eu>
[R-Refactoring] Added support for file scope in rename wizard
[R-Search] Improved scope handling for R element search

Signed-off-by: Stephan Wahlbrink <sw@wahlbrink.eu>