Revert "Revert "pulsar_crosscorr_v2: toplist functionality now compiles.  Still needs testing""

This reverts commit ad4a73a4ddc32d5dc11c8ffb99041bb2d4397a05.
Revert "Revert "pulsar_crosscorr_v2: added sorting and writing of toplist file""

This reverts commit 133252465ecf1e10ad3387e82d7b3ec4d2d2f9f8.
lalapps_pulsar_crosscorr_v2: i. added output file of test script to make clean target ii. added cast to void so code can complile on OSX