RFR: 8042872: Fix raw and unchecked warnings in sun.applet

[Henry Jen]

Hi,

Please review another webrev to clean up rawtypes and unchecked warning, 
this time for sun.applet.

The webrev applied to both jdk9/dev and jdk9/client cleanly, I am not 
sure which repo should the webrev go once pass review.

Webrev can be found at
http://cr.openjdk.java.net/~henryjen/jdk9/8042872/0/webrev/

Please also let me know any particular test I should do other than 
regular jprt.

Cheers,
Henry