Revert "Fix warnings about unchecked conversion of MergeResult"

This reverts commit 979fa19110.
Breaks API.

Change-Id: I54af657898d49f64d6906fe3edfb6b08e996d901

org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/MergeAlgorithmTest.java

 	}
 
 	private String merge(String commonBase, String ours, String theirs) throws IOException {
-		MergeResult<RawText> r = new MergeAlgorithm().merge(RawTextComparator.DEFAULT,
+		MergeResult r = new MergeAlgorithm().merge(RawTextComparator.DEFAULT,
 				T(commonBase), T(ours), T(theirs));
 		ByteArrayOutputStream bo=new ByteArrayOutputStream(50);
 		fmt.formatMerge(bo, r, "B", "O", "T", Constants.CHARACTER_ENCODING);

org.eclipse.jgit/src/org/eclipse/jgit/merge/MergeFormatter.java

 	 *            metadata
 	 * @throws IOException
 	 */
-	public void formatMerge(OutputStream out, MergeResult<RawText> res, String baseName,
+	public void formatMerge(OutputStream out, MergeResult res, String baseName,
 			String oursName, String theirsName, String charsetName) throws IOException {
 		List<String> names = new ArrayList<String>(3);
 		names.add(baseName);