JAXP RFR: 8000172 : 2 SAX features does not work properly

[Joe Wang]

This is an issue found while I was working with SQE to expand test 
coverage. For a non-validating parser, when load-external-dtd is false, 
entity references are skipped. However, the skippedEntity() event was 
not reported.

The problem was due to missing infoset augmentations when document 
handler's startGeneralEntity/endGeneralEntity were called.  The fix 
therefore is simply add the arguments.

webrev: http://cr.openjdk.java.net/~joehw/jdk8/8000172/webrev/

Please review.

Thanks,
Joe