[OpenJDK 2D-Dev] JDK 9: RFR: 8033716: Fix raw and unchecked lint warnings in com.sun.imageio

[Henry Jen]

Hi,

Please review the webrev to clean up raw and unchecked warnings in 
com.sun.imageio packag at,

http://cr.openjdk.java.net/~henryjen/jdk9/8033716/0/webrev/

The more significant change in this webrev is that I have changed the 
clone() method of MarkerSegment-derived classes to return exact type 
rather than Object. Otherwise, it's basically add type information and 
eliminate cast no longer needed.

Cheers,
Henry