Improved the speed of operation of all functions for price indices.
Function data_matching() has been modified and now it is much more faster,
Examples concerning chain indices have been modified and now they are less time-consuming while checking,
New data set is added (dataU)
New functions for scanner data processing are added (data_unit and data_norm)
Access to HASP and WISP methods has been added in the price_index() function and now price_indices() works correctly,
The default value and the meaning of the sensitivity parameter in data_preparing() and model_classification() functions have been corrected.