Make well groups.

- Read group names
- introduce blocks for groups of wells.
Add well labels array.

- get flatten block numbers
Trying to use BlockSelectionSource

- no success, do not know how to provide input dataset
- merge_groups.py - ProgrammableFilter to make single PolyData from
  BlockDataset produced by eclipse reader
Leave reader without client side hacking.
- move all client side postprocessing to separate script
  that can be run as a macro
- debug the client side, overcome unpleasant offset
  of displayed selection
Add tests.

- add test unrst file
Add documentation.
Remove properties of the reader form the panel.
Remove examples.
Add project report.

(in czech)