New query: Don't use library annotation.

ql/src/queries/style/LibraryAnnotation.ql

@@ -0,0 +1,15 @@
+/**
+ * @name Use of deprecated annotation
+ * @description The library annotation is deprecated
+ * @kind problem
+ * @problem.severity warning
+ * @id ql/deprecated-annotation
+ * @tags maintainability
+ * @precision very-high
+ */
+
+import ql
+
+from AstNode n
+where n.hasAnnotation("library") and not n.hasAnnotation("deprecated")
+select n, "Don't use the library annotation."