Fix compiler (eclipse) warnings in (generated) jute code

Fixes for compiled jute parser:

• missing generic types
• added @SuppressWarnings("unused") because javacc adds a dead throws clause at the
  end of functions.

Fixes for code compiled by jute compiler:

• remove import java.util.* and use full ref to java.util.Arrays

One warning fixed in non-compiled code:
src/java/main/org/apache/jute/compiler/JRecord.java

Rationale: The warnings in your IDE (eclipse) get useless if there are tons of them. This patch reduces many of them. Another issue with patch will reduce them to 8.