* Bug: In Hurricane::DbU, replace long by DbU::Unit (aka int64_t) in all
remaining occurrences.
* Change: In Hurricane::DbU::getValueString(), rewrite using ostringstream.
* Change: In Hurricane, in PyHurricane.h, PyAny_AsLong<> template to
convert any kind of Python integer into DbU, making sure we always
use 64 bits integers (long long for 32 bits and long for 64 bits).
PyDbU_FromLong<> template to peform the reverse, DbU to Python
integer in 64 bits (either using PyLong_FromLong() or
PyLong_FromLongLong()).
* Bug: In Isobar, in PyArg_ParseTuple(), never use the "l" direct
converter when reading a DbU. Instead read a PyObject then convert
using PyAny_AsLong<>. This ensure to never do a truncature.