Removed the invalid label from the Item Editor.
Added priceEntrySetPrice() and changed itemeditor.c to use it.
Removed priceEntrySetText(), added priceEntryClear(), and changed itemeditor.c to use it.
Changed the one alert dialog with a variable name prompt to have a variable named alert; this is to split out the question alerts into a separate function.
Split out the alerts asking for confirmation into their own file and adjusted itemeditor.c to use them.
Cleaned up newItemEditor() a bit.
Moved the setting of items table model into items.c to reduce the need for itemsModel(). itemeditor.c has this done to it already. I don't think I can clean up itemeditor.c much more...