Updates to JDK9 Early Access documentation - Improved G1 documentation

[Thomas Schatzl]

Hi all,

  yesterday JDK9 early access documentation has been made available at 
http://docs.oracle.com/javase/9/ .

This includes the GC tuning guide at http://docs.oracle.com/javase/9/gc
tuning/toc.htm: while we tried to improve the documentation throughout,
we are aware that there is still lots of work to do on the overall
document.

However, we basically rewrote chapter 9 "Garbage-First Collector" and
chapter 10 "Garbage-First Garbage Collector Tuning" to coincide with G1
becoming the default collector.

Particularly the tuning chapter tries to collect answers to many
problems people had with G1 that have been discussed in the last few
years, also and in particular on this mailing list. (Thanks everyone
for coming here and talking about issues you had)

I hope the document is a significant improvement on the old one for
you.

Feedback about any part of it is highly appreciated. If you see
anything missing or wrong, we will try to fix it or at least save your
feedback for the next bigger update.

Thanks,
  Thomas

P.S: And yes, chapter 10 can be seen as a to-do list for future
improvements :)