Fix grammar for annotation members

- The lookahead (3 tokens) was too small, and without reaching the opening
    parenthesis assumed it was parsing a method and not a field.
 - Using a larger lookahead solves the issue.
 - Fixes #206

pmd-java/etc/grammar/Java.jjt

@@ -1,4 +1,9 @@
 /**
+ * Change lookahead for AnnotationMethodDeclaration in AnnotationTypeMemberDeclaration.
+ * Bug #206
+ *
+ * Juan Martin Sotuyo Dodero 01/2017
+ *====================================================================
  * Allow method references to specify generics.
  * Bug #207
  *
@@ -2282,7 +2287,7 @@ void AnnotationTypeMemberDeclaration():
 {
  modifiers = Modifiers()
  (
-   LOOKAHEAD(3) AnnotationMethodDeclaration(modifiers)
+   LOOKAHEAD(Type() <IDENTIFIER> "(") AnnotationMethodDeclaration(modifiers)
   |
    ClassOrInterfaceDeclaration(modifiers)
   |