roadmap: Move incomplete 3.5 items to 3.6

Not sure if any of these should be removed instead, but at least
reflecting they won't be in 3.5.

We can also drop 3.5 now since the one remaining item is in the 3.5-rc
releases.

Change-Id: Ifd8b1bef9d7d8fa02551aaaa0ca96717dfb43162
1 file changed