Cleanup Warning in java.sql, javax.sql, com.sun.rowset packages

Clean up javac build warnings in java.sql, javax.sql, com.sun.rowset packages.

make/com/sun/rowset/Makefile
make/java/sql/Makefile
make/javax/sql/Makefile
src/share/classes/com/sun/rowset/CachedRowSetImpl.java
src/share/classes/com/sun/rowset/JdbcRowSetImpl.java
src/share/classes/com/sun/rowset/JoinRowSetImpl.java
src/share/classes/com/sun/rowset/internal/SyncResolverImpl.java
src/share/classes/java/sql/CallableStatement.java
src/share/classes/java/sql/Date.java
src/share/classes/java/sql/DriverManager.java
src/share/classes/java/sql/PreparedStatement.java
src/share/classes/java/sql/ResultSet.java
src/share/classes/javax/sql/rowset/BaseRowSet.java