Work on the Market Interface (feel free to test it out so far, can't purchase items through the UI yet), More on UITable (needs work on headers still).

* Tables can now have headers (the layouts will require some more work before read to be used formally).
* Finished Market offers display, Item details display, and Item statistics display.
* Added getSelectedWidget to UIRadioGroup class.

Market TODO:
* Create buy/sell offer.
* Purchase sale offer or accept purchase offer.
* More item filtering features (weapons, types, depot only, vocation, etc).
* Item searching feature.
* View your offers (history/current).
* UI touch ups and optimizations.

modules/corelib/ui/uiradiogroup.lua

@@ -4,6 +4,7 @@ UIRadioGroup = newclass()
 function UIRadioGroup.create()
   local radiogroup = UIRadioGroup.internalCreate()
   radiogroup.widgets = {}
+  radiogroup.selectedWidget = nil
   return radiogroup
 end
 
@@ -43,3 +44,7 @@ function UIRadioGroup:selectWidget(selectedWidget)
 
   signalcall(self.onSelectionChange, self, selectedWidget, previousSelectedWidget)
 end
+
+function UIRadioGroup:getSelectedWidget()
+  return self.selectedWidget
+end