Added the refactored sharing capability to functions.

...s/src/com/oracle/truffle/r/nodes/unary/DuplicateNode.java

...ime/src/com/oracle/truffle/r/runtime/data/RDataFrame.java

...me/src/com/oracle/truffle/r/runtime/data/RExpression.java

...untime/src/com/oracle/truffle/r/runtime/data/RFactor.java

...time/src/com/oracle/truffle/r/runtime/data/RFunction.java

...time/src/com/oracle/truffle/r/runtime/data/RLanguage.java

...e/src/com/oracle/truffle/r/runtime/data/RLanguageRep.java

...ntime/src/com/oracle/truffle/r/runtime/data/RPromise.java

...ime/src/com/oracle/truffle/r/runtime/data/RShareable.java

...acle/truffle/r/runtime/data/RSharingAttributeStorage.java

...untime/src/com/oracle/truffle/r/runtime/data/RVector.java