Merge the following revisions from 3_9_BRANCH to trunk:
r13682  Initial cut at 3.9.0 release notes.
r13683  Remove duplicate NEWS entries for 3.9.0.
r13689  Minor docs/NEWS fixes
r13690  Documentation updates for 3.9.0.
r13691  More documentation updates, re leak-checker changes
r13692  NEWS: Note increased max mem size.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13724 a5019735-40e9-0310-863c-91ae7b9d1cf9