Slicer/Slicer — pull request #73 by lassoan (2013-10-11 19:15:09+00:00)
Title: ENH: Don't batch process when show/hide only a few child nodes

When there are many child nodes in a hierarchy then show/hide is much more efficient if batch processing is enabled.
However, if there are few nodes only then a full refresh at the end of a batch processing takes longer than doing the update on each node separately.
Count the number of child nodes and if there are less than 30 then update each node separately.