dsky_clock: hide widgets before building layout

so that the layout doesn't account for the widget bar when `dsky_clock`
is fast loaded into.

Also handle the hardware button trough the layout library instead of
`Bangle.setUI`. Also set `Bangle.CLOCK` directly.

Author: thyttan

apps/dsky_clock/app.js

@@ -14,6 +14,10 @@ const LightFont='Teletext5x9Ascii';
 const DataFont='7x11Numeric7Seg:2';
 var mode = 0;
 
+Bangle.CLOCK = 1;
+Bangle.loadWidgets();
+require("widget_utils").swipeOn(); // hide widgets, make them visible with a swipe
+
 var layout = new Layout(
   {type:"h", c:[
     {type:"",width:6},
@@ -54,7 +58,10 @@ var layout = new Layout(
       ]},
     {type:"",width:5},
   ],
-  lazy:true});
+  lazy:true}, 
+  {btns:[
+  {label:"", cb: Bangle.showLauncher}
+], lazy:true});
 layout.update();
 
 //support functioe_ns
@@ -346,12 +353,6 @@ function queueDraw() {
   }, 60000 - (Date.now() % 60000));
 }
 
-// Show launcher when middle button pressed
-Bangle.setUI("clock");
-
-Bangle.loadWidgets();
-require("widget_utils").swipeOn(); // hide widgets, make them visible with a swipe
-
 Bangle.on('lock',on=>{
   mode = 0;
   drawMain(); // draw immediately