Huuuuge commit, but still work in progress:

* Categories can now be "unfrozen" so that we can go back to config mode

* KO_Config can now return the total number of groups in the configuration

* Introduced initial code for an array of list boxes for defining group assignments

* Introduced initial code for a dialog box for defining group assignments

* Extended the CatTabWidget to call the new dialog if the user hits the "Run!" button (including "freezing" the category before and "unfreezing" it in case the user cancled the operation)

* Added -- as a proof-of-concept -- a delegate for rendering player entries in the player list view