second draft of 10.7.1 release notes

[Rick Hillegas]

I have posted a new version of the 10.7.1 release notes, incorporating 
Dag's comments: 
https://svn.apache.org/viewvc/db/derby/code/trunk/RELEASE-NOTES.html?view=co

Please let me know how I can improve these release notes further. In 
particular, I wordsmithed the detailed release notes for the following 
issues. Hopefully, I haven't garbled the result, but it would be good if 
the original authors could verify that:

DERBY-4786
DERBY-4777
DERBY-4577

Thanks,
-Rick