Revert "pulsar_crosscorr_v2: added sorting and writing of toplist file"

This reverts commit 2d927c1e7b11d3170396b4e10363591dddd89644.
Revert "pulsar_crosscorr_v2: toplist functionality now compiles.  Still needs testing"

This reverts commit df754097f2364c7e4e6f84e46f7f4eb3eb8c0627.