Allow Spinjump from Vine/Net/Etc.

Note that the net hitting animation will not briefly prevent you from spin-jumping as it would usually with normal-jumping. A side effect of this is that, if you spin too soon after hitting a net door, the animation will be cut short and the door won't turn. It's a small window for it to happen and it's pretty inconsequential, but thought I'd mention it anyway.

This is a rather simple but still welcome effect. I can see it being applied in kaizo or similarly hard levels.