subset of bigger one.

Master

@Tyagov 
This Merge request adds
 * Data Array Line -> to get a view into data array in any dimension defined by numpy indexing syntax
 * Data Event Module -> to store user-entered information about monitoring, for example on missing data

The merge request also fixes getSize on empty data array and it fixes http range requests for some arrays.

See merge request !9

reason: previous way did not work for all kind of arrays

To avoid random test failures due to test execution we make start date one day before. This commit only fixes test.

Add comments to do.

This script should only append data to stream and NOT do any transformations on it keeping a simple rule of ERP5: save exactly what was entered by user or passed to us by remote agent (fluentd).

add array preview listbox to Data Array View

The listbox shows lines for all indexes in the first dimension of the ndarray and up to 100 columns for the second dimension.

See merge request !8

The listbox shows lines for all indexes in the first dimension of the ndarray and up to 100 columns for the second dimension.

Call pure transformation in an activity rather than execute in current transaction. This way we split ingestion part from transformation part.
Note: this commit will serialize argument_list to activity's mysql table in case of big packets this can be slow, in case of small appends it can be acceptable.
Instead we should call with start and end offset only and data should be read from Data Stream itself (WIP).

Raise in case of improper server side configuration so sender is aware rather than silently return nothing and fool sender it's all ok.
Pylint.

Remove an example that stored twice the RAM memory zeros in ZODB's root as this can quickly run out of space any Wendelin instance.
Use ERP5-ish API to work with Data Arrays