add dice dataflow
stringify Data::Frame
use confess instead of die
change row_names to set data to PDL
subset and select_rows return a Data::Frame with slices of the original
make 0-dim piddles stringifiable
add cpanfile
add version to dist.ini
misc
test stringifiable for PDL::SV
test subset
column() returns a PDL now [ not a Data::Perl::array() ]
fix test plan
spacing
PDL::Factor: use hashref PDL init instead of MooX::InsideOut
use PDL::uniq
add test
fix test