owlps-aggcheck uses the timestamp alone to identify requests, which
causes problem in case two requests have the same timestamp. This commit
allows the script to detect duplicated timestamps, and documents the
bug.
Add owlps-aggcheck.pl in the new scripts/ directory. As its name
indicates, this script allows one to analyse an aggregation file in
various ways: print human-readable information, extract signal strength
distribution, or extract the number of packets per request and per
capture point.