Fixes #4052
Fixes #4052

After block level BBCs that trim outside whitespace but do not have required parents, such as [quote], [float], etc., we only want to trim one line of whitespace. But after ones that do have required parents, such as [li], [td], etc., we want to trim out all trailing whitespace and line breaks until we reach the next element. For reasons I haven't bothered to fully figure out, something about the way parse_bbc() worked in SMF 2.0.x made that work even though the code said to trim all the trailing whitespace regardless. At any rate, in 2.1 we need to state explicitly what we actually want to happen, so this PR does that.

Signed-off-by: Jon Stovell <5fe09b7d9f00fd95250ae2a73993b352b084988d@gmail.com>

StealthWombat/SMF2.1-more-forkery,StealthWombat/SMF2.1-more-forkery