Backport Psych 1.3.3 and 1.3.4 to stable branch
Hi, I'd like to backport Psych 1.3.3 and 1.3.4 to the ruby_1_9_3 branch. It's 10 commits:
r36583, r36458, r36414, r36103, r35690, r35681, r35658, r35657, r35655, r35492
I've attached a patch. Can someone please review? Thank you!