* lib/csv.rb (CSV.parse): [CAUTION] behavior changed.  in the past,
          CSV.parse accepts a filename to be read-opened (it was just a
          shortcut of CSV.open(filename, 'r')).  now CSV.parse accepts a
          string or a stream to be parsed e.g.
          CSV.parse("1,2\n3,r") #=> [['1', '2'], ['3', '4']]

        * lib/csv.rb: CSV::Row and CSV::Cell are deprecated.  these classes
          are removed in the future.  in the new csv.rb, row is represented
          as just an Array.  since CSV::Row was a subclass of Array, it won't
          hurt almost all programs except one which depended CSV::Row#match.
          and a cell is represented as just a String or nil(NULL).  this
          change will cause widespread destruction.

              CSV.open("foo.csv", "r") do |row|
                row.each do |cell|
                  if cell.is_null       # using Cell#is_null
                    p "(NULL)"
                  else
                    p cell.data         # using Cell#data
                  end
                end
              end

            must be just;

              CSV.open("foo.csv", "r") do |row|
                row.each do |cell|
                  if cell.nil?
                    p "(NULL)"
                  else
                    p cell
                  end
                end
              end

        * lib/csv.rb: [CAUTION] record separator(CR, LF, CR+LF) behavior
          change.  CSV.open, CSV.parse, and CSV,generate now do not force
          opened file binmode.  formerly it set binmode explicitly.

          with CSV.open, binmode of opened file depends the given mode
          parameter "r", "w", "rb", and "wb".  CSV.parse and CSV.generate open
          file with "r" and "w".

          setting mode properly is user's responsibility now.

        * lib/csv.rb: accepts String as a fs (field separator/column separator)
          and rs (record separator/row separator)

        * lib/csv.rb (CSV.read, CSV.readlines): added.  works as IO.read and
          IO.readlines in CSV format.

        * lib/csv.rb: added CSV.foreach(path, rs = nil, &block).  CSV.foreach
          now does not handle "| cmd" as a path different from IO.foreach.
          needed?

        * test/csv/test_csv.rb: updated.

        * test/ruby/test_float.rb: added test_strtod to test Float("0").


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@6424 b2dd03c8-39d4-4d8f-98ff-823fe69b080e