Fixed some errors in the Windows code.

windows/checkbox.c

@@ -94,7 +94,7 @@ static void setChecked(uiCheckbox *c, int checked)
 	SendMessage(hwnd, BM_SETCHECK, check, 0);
 }
 
-uiControl *uiNewCheckbox(const char *text)
+uiCheckbox *uiNewCheckbox(const char *text)
 {
 	struct checkbox *c;
 	uiWindowsNewControlParams p;

windows/entry.c

@@ -42,7 +42,7 @@ static void setText(uiEntry *e, const char *text)
 	uiWindowsControlSetText(uiControl(e), text);
 }
 
-uiControl *uiNewEntry(void)
+uiEntry *uiNewEntry(void)
 {
 	struct entry *e;
 	uiWindowsNewControlParams p;

windows/label.c

@@ -41,7 +41,7 @@ static void setText(uiLabel *l, const char *text)
 	uiWindowsControlSetText(uiControl(l), text);
 }
 
-uiControl *uiNewLabel(const char *text)
+uiLabel *uiNewLabel(const char *text)
 {
 	struct label *l;
 	uiWindowsNewControlParams p;