Cleaned up Python bindings to restore functionality:
* StaticPersistence is iterable, its nodes are usable (sign, pair, cycle)
* StaticPersistence knows how to map its nodes into Filtration indices
* moved PythonCmp into utils.h
* minor cosmetic changes
#ifndef __PYTHON_UTILS_H__
#define __PYTHON_UTILS_H__
struct PythonCmp
{
template<class T>
bool operator()(T x1, T x2) const { return cmp_(x1, x2) < 0; }
PythonCmp(object cmp): cmp_(cmp) {}
object cmp_;
};
#endif