Introduce SubDumper.p.skip, .unskip, .prune
Introduce SubDumper.p.skip, .unskip, .prune

These will be the new implementation of the corresponding methods on Dumper.

NeilFraser/CodeCity,google/CodeCity,NeilFraser/CodeCity,google/CodeCity,google/CodeCity,NeilFraser/CodeCity,google/CodeCity,NeilFraser/CodeCity