[Poshuku CW] Handle child frames.
[Poshuku CW] Somewhat nicer code.
[Poshuku CW] Remove elems by hiding them.
[Poshuku CW] Notify about filter changes.
[Poshuku CW] Matches() doesn't need to be Core member.
[Poshuku CW] Don't modify the list on hiding.
[Poshuku CW] Threaded ShouldReject().
[Poshuku CW] Smart chunk size calculation.
[Poshuku CW] Removed old single-threaded commented code.