Removed unnessary public fields from StyleSheet
Inlined the call to the getAllSelectors(), so will be able to abstract
it
Made an nested static class (BatchGroupingRefactoringResult) so will be
able to remove public ints  from StyleSheet
Abstracted the call to getAllSelectors() in the StyleSheet
Added StyleSheet and Selector Numbers to the Selector
Fixed the issue with number of applied refactorins
Abstracted getDeclarations() call in Selector, Added Declaration Number
to Declaration
- Fixed the issue with declaration and selector numbers
- Fixed a typo in the comment of the Declaration class
Abstracted support in Item data strcutres
Added getDeclarationNumber() method to Declarations
Abstracted getBaseSelectors() in GroupingSelector
Added corresponding size() method
Supported font-family in MultiValued declarations
Start using selector and declaration numbers in refactorings
Moved isAppliable() method to ItemSet
Commented some unnecessary code
Defined and added a file logger