New version of FastCube VCL - 2.6

In the new version we added an ability to restrict user from slice reconfiguration.
Restrictions should be set for each zone separately in the zone Restrictions property.

For the moment 3 types of restrictions are implemented:

- zrDontMoveItems - disable field list change for the zone. The restrictions prevents from add, remove and move fields in the zone.
- zrDontShowPopupMenu - disable zone context menu popup.
- zrDontEditItemProperties - disable zone/field property editor showing.

Several restrictions can be set simultaneously.

Added an ability to control zone field list change by TfcxSlice events:
-OnBeforeRemoveSliceFieldFromRegion: TfcxSliceFieldRegionChange - is called before field remove.
-OnBeforeAddSliceFieldToRegion: TfcxSliceFieldRegionChange - is called before field add.
-OnAfterAddSliceFieldToRegion: TfcxSliceFieldRegionChanged - is called after field add.
TfcxSliceFieldRegionChange = procedure(ASliceFieldName: String; ARegionOfField: TfcxRegionOfField; var AAllow: Boolean) of Object;
TfcxSliceFieldRegionChanged = procedure(ARegionFieldIndex: Integer; ARegionOfField: TfcxRegionOfField) of Object;

OnBefore* events allow to cancel operation with field ASliceFieldName in the region ARegionOfField by changing AAllow to False.

Fixed slice fields format handling.
Now slice field format change instatly refreshes the slice grid, and does not change the format of other fields with the same data type.
Additionally to that slice field format is saved and restored to/from the schema.

Added new measure field property:
TfcxMeasureField.ChangeNullToZero: boolean
When the property is set to True the empty measure cells (cells which have no data) are shown with the value 0.

For more details check the full list of changes.