控件代码分分布到场景代码中，优化控件相关代码

parts/scenes/history.lua

@@ -55,4 +55,10 @@ function Pnt.history()
 	setFont(20)
 	local S=sceneTemp
 	gc.print(S.text[S.pos],40,50)
-end
+end
+
+WIDGET.init("history",{
+	WIDGET.newKey({name="prev",		x=1155,	y=170,w=180,font=65,code=WIDGET.lnk.pressKey("up"),hide=WIDGET.lnk.STPeq("pos",1)}),
+	WIDGET.newKey({name="next",		x=1155,	y=400,w=180,font=65,code=WIDGET.lnk.pressKey("down"),hide=function()return sceneTemp.pos==#sceneTemp.text end}),
+	WIDGET.newButton({name="back",	x=1140,	y=640,w=170,h=80,font=40,code=WIDGET.lnk.BACK}),
+})