core: hiding implementation of classes from tag.hpp
warning fix
code cleanup
code format
comments
gui: Introducing TagsOperator
tr: ts file update
gui: TagsOperator refactor
code cleanup
gui: introduducing ITagOperator
gui: TagsOperator: inheriting from ITagsOperator
gui: TagsModel: operating on provided ITagsOperator
gui: ITagsOperator: introducing operateOn()
gui: TagEditorWidget: passing TagsOperator to model
gui: TagsModel: preparations for tags updating
core: Tag::Info: consts added
gui: TagsOperator: introducing updateTag()
CMake: fixing link problems
gui: TagsEditor: TagsModel: updating tag value
core: introducing TagValue as a replacer to ValuesSet and TagValueInfo