Add SkMatrix44::setTranspose

It turned out that adding getDouble(...) and setDouble(...) made this change
easier, so I've included that in this cl as well.

Review URL: https://codereview.appspot.com/6845048

git-svn-id: http://skia.googlecode.com/svn/trunk@6424 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed