Specify RevisionSyntaxException message in Repository#resolve

This does not address all cases where no message is specified, only
cases where Repository#isValidRefName returns false.

Change-Id: Ib88cdabfdcdf37be0053e06949b0e21ad87a9575
Signed-off-by: Grace Wang <gracewang92@gmail.com>

org.eclipse.jgit/src/org/eclipse/jgit/lib/Repository.java

 							// detached
 							name = Constants.HEAD;
 						if (!Repository.isValidRefName("x/" + name)) //$NON-NLS-1$
-							throw new RevisionSyntaxException(revstr);
+							throw new RevisionSyntaxException(MessageFormat
+									.format(JGitText.get().invalidRefName,
+											name),
+									revstr);
 						Ref ref = getRef(name);
 						name = null;
 						if (ref == null)
 						if (name.equals("")) //$NON-NLS-1$
 							name = Constants.HEAD;
 						if (!Repository.isValidRefName("x/" + name)) //$NON-NLS-1$
-							throw new RevisionSyntaxException(revstr);
+							throw new RevisionSyntaxException(MessageFormat
+									.format(JGitText.get().invalidRefName,
+											name),
+									revstr);
 						Ref ref = getRef(name);
 						name = null;
 						if (ref == null)
 			return null;
 		name = revstr.substring(done);
 		if (!Repository.isValidRefName("x/" + name)) //$NON-NLS-1$
-			throw new RevisionSyntaxException(revstr);
+			throw new RevisionSyntaxException(
+					MessageFormat.format(JGitText.get().invalidRefName, name),
+					revstr);
 		if (getRef(name) != null)
 			return name;
 		return resolveSimple(name);