implement advance() in XS
optimize advance()
add explicit VERSION to all Makefile.PL

Started noticing install failures. The VERSION key seems to be required
for XSUB extensions. Found no better solution than to enter explicit
VERSIONs, but at least Test::Version will help me catch possible version
mismatches.
do not compare automatic number of bins with hist()

Disabled two tests that tested whether the number of bins determined by
PDL::NDBin, when it was not supplied, matches the number of bins
determined by hist(). The tests were giving test failures with the
newest development releases of PDL (2.4.11_007 and 2.4.11_008 among
them), because the bin number determination has been changed. Since
PDL's behaviour was not documented, relying on it was not a good idea.
Hence, the tests were disabled. Updated the user documentation to match
the code.
add tests with 1 million bins to benchmark
update user manual with results of the benchmark
update changelog
v0.008

 - implemented the advance() method of PDL::NDBin::Iterator in XS. This
   improves the performance of PDL::NDBin for very large bin numbers greatly,
   and also reduces the overhead (for very small datafiles) somewhat. The user
   manual has been updated with the latest results. (Edward Baudrez)
 - fixed a test that started failing with the latest PDL development releases
   (Edward Baudrez)