Lose redundant std::moves
Per @srh, underscore suffix instead of prefix
Expand on why we need a fake, here.
STL iterators grew -> when I wasn't looking
Remove redundant XXX
Set up serialization & unlimited amounts.
Change feeds should use default limits rather than user limits.

This is because bits & pieces are shared instead of being completely
owned by some user request somewhere; in particular, feed_ts.
Convert these to scoped_ptrs
Add explanatory comment.
Per @srh use a pointer for this visitor.
Be less silly with these visitors
No, pointers are a bad idea here.
Derp, use right macro
This visitor should use a pointer, too.