move REngine to canonical package

com.oracle.truffle.r.shell/src/com/oracle/truffle/r/engine/REngine.java → com.oracle.truffle.r.shell/src/com/oracle/truffle/r/shell/REngine.java

@@ -20,7 +20,7 @@
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
-package com.oracle.truffle.r.engine;
+package com.oracle.truffle.r.shell;
 
 import java.io.*;
 import java.util.*;

com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/generate/FastRSession.java

@@ -24,6 +24,7 @@ package com.oracle.truffle.r.test.generate;
 
 import com.oracle.truffle.r.engine.*;
 import com.oracle.truffle.r.runtime.*;
+import com.oracle.truffle.r.shell.*;
 
 public class FastRSession implements RSession {