Moved lsfiltration.py into examples/pl-functions + added lscubes.py example (cubical lower-star filtration)
#include <utilities/log.h>
#ifdef LOGGING
static rlog::RLogChannel* rlFiltration = DEF_CHANNEL("topology/filtration/info", rlog::Log_Debug);
static rlog::RLogChannel* rlFiltrationDebug = DEF_CHANNEL("topology/filtration/debug", rlog::Log_Debug);
#endif // LOGGING