* Allow single-cell checks on conditional styles, even when the style is configured for a range of cells
* Work on the CellMatcher logic to evaluate Conditionals for a cell based on its value, and identify which conditional styles should be applied
* Refactor style merging and cell matching for conditional formatting into separate classes; this should make it easier to test, and easier to extend for other CF expressions subsequently
* Added support for containsErrors and notContainsErrors
* Initial work on a wizard to help simplify created Conditional Formatting rules, to ensure that the correct expressions are set
* Further work on extending the Conditional Formatting rules to cover more of the options that are available in MS Excel
* Prevent phpcs-fixer from removing class @method annotations, used to identify the signature for magic methods used in Wizard classes
* Implement `fromConditional()`` method to allow the creation of a CF Wizard from an existing Conditional
* Ensure that xlsx Reader picks up the timePeriod attribute for DatesOccurring CF Rules
* Allow Duplicates/Uniques CF Rules to be recognised in the Xlsx Reader
* Basic Xlsx reading of CF Rules/Styles from <extLst><ext><ConditinalFormattings> element, and not just the <ConditinalFormatting> element of the worksheet
* Add some validation for operands passed to the CF Wizards
- remove any leading ``=` from formulae, because they'll be embedded into other formulae
- unwrap any string literals from quotes, because that's also handled internally
Handle cross-worksheet cell references in cellReferences and Formulae/Expressions
* re-baseline phpstan
* Update Change Log with details of the CF Improvements
Mark Baker