New dialog box units used to add, rename and delete user-defined categories, along with an abstract base class for the dialog boxes and two frame units that contain and manage controls used in the dialog dialog boxes:
* FmCategoryEditDlg provides an abstract base class for the three main dialog boxes.
* FmAddCategoryDlg implements the "add category" dialog.
* FmDeleteCategoryDlg implements the "delete category" dialog.
* FmRenameCategoryDlg implements the "rename category" dialog.
* FrCategoryDescEdit implements a frame containing an edit box that receives category descriptions. The frame checks the entry for validity.
* FrCategoryList implements a frame containing a list box that displays available categories.