DataArray: get array slice by HTTP Range Request

See merge request !5

Allow to pass additional keyword arguments to transformation script

See merge request !4

Conflicts:
	bt5/erp5_wendelin/SkinTemplateItem/portal_skins/erp5_wendelin/DataStream_transform.xml

A simple example of a map reduce job that stores intermediate result to an Active Process and calculates average on slices of a ZBig Array.

Allow these portal types to be used as Predicates to define grouping of "data documents" within the system.

Proxify title in Data Array View

Proxification

See merge request !2

Display source/destination instead of *_section in Data Supply Line listbox

To complement the change from source/destination_section -> source/destination in Data Supply Line

See merge request !1

Instead of verifying only min/max/len of the result, we can verify that the
result is explicitly the array we expect, especially that it is easier to do
and less lines with just appropriate arange() and array_equal().

/cc @Tyagov

As explained in previous commit, real_data tail was ending without \n

    99988,99989\n99990,99991,99992,99993,99994,99995,99996,99997,99998,99999\n100000

and because DataStream_copyCSVToDataArray() processes data in full lines only,
the tail was lost.

Fix t by making sure the last line is always terminated properly with \n.

/cc @Tyagov

Consider this:

    In [1]: l = range(100000)

    In [2]: min(l)
    Out[2]: 0

    In [3]: max(l)
    Out[3]: 99999

    In [4]: len(l)
    Out[4]: 100000

so if we assert that zarray min=0 and max=99999 the length should be max+1
which is 100000.

NOTE the length is not 100001, as one would guess from test number sequence
created at the beginning of the test:

  def chunks(l, n):
    """Yield successive n-sized chunks from l."""
    for i in xrange(0, len(l), n):
      yield l[i:i+n]

  ...

    number_string_list = []
    for my_list in list(chunks(range(0, 100001), 10)):
      number_string_list.append(','.join([str(x) for x in my_list]))
    real_data = '\n'.join(number_string_list)

because processing code "eats" numbers till last \n and for 10001 last \n is located before 100000:

  99988,99989\n99990,99991,99992,99993,99994,99995,99996,99997,99998,99999\n100000

I will fix input data generation in the following patch.

/cc @Tyagov

When we conditionally create new BigArray for appending data, we should create
it as empty, because in DataStream_copyCSVToDataArray() creation is done lazily
only when destination array is not yet initialized and we anyway append data to
the array in the following code block.

Creating BigArray with initial shape of appending part will result in
destination array being longer than neccessary by first-appended-chunk length
with this-way-introduced extra header reading as all zeros.

Fix it.

/cc @Tyagov

source_section -> source
destination_section -> destination

Stop use \n character as ingestion delimiter, only use for .CSV format where it's part of the structure of a file.

Clean up iterate script implementation. No need of own array property type when we can use more generic object.