9webdraw: trap tab and backspace in keydown rather than keypress.
This stops Chrome from firing the default action.
Also call preventDefault()/stopPropagation() on mouse-fkeys.
.

Reference: /n/atom/patch/applied/9wd-kbd-trap
Date: Mon May 19 20:55:59 CES 2014
Signed-off-by: root@davidrhoskin.com

--- /usr/web/9wd/js/cons.js	Mon May 19 20:53:21 2014
+++ /usr/web/9wd/js/cons.js	Mon May 19 20:53:23 2014
@@ -10,11 +10,11 @@
 	var compose = new Compose(this);
 
 	this.log = function(s){
-		if(this.debug){
+		//if(this.debug){
 			var span = document.createElement("span");
 			span.textContent = s;
 			this.elem.appendChild(span);
-		}
+		//}
 	}
 
 	this.write = function(s){
@@ -30,6 +30,8 @@
 	this.handlekeys = function(e, dir){
 		if(!mouse.handlefkeys(e, dir == cons.kbd.down?
 			mouse.states.down : mouse.states.up)){
+			e.preventDefault();
+			e.stopPropagation();
 			return 0;
 		}
 
@@ -57,6 +59,12 @@
 			e.stopPropagation();
 			return 0;
 		}
+
+		if(dir == cons.kbd.up){
+			e.preventDefault();
+			e.stopPropagation();
+			return 0;
+		}
 		return 0;
 	}
 
@@ -65,6 +73,10 @@
 		switch(e.which){
 		case 0:
 			break;
+		case 8:
+			return "\b";
+		case 9:
+			return "\t";
 		case 13:
 			return "\n";
 		case 18:
--- /usr/web/9wd/js/init.js	Mon May 19 20:53:26 2014
+++ /usr/web/9wd/js/init.js	Mon May 19 20:53:28 2014
@@ -3,7 +3,7 @@
 }
 
 function addevent(elem, evt, handler){
-	elem.addEventListener(evt, handler, true);
+	elem.addEventListener(evt, handler, false);
 }
 
 /* this should not be necessary, but */
@@ -22,6 +22,7 @@
 
 window.onload = function(){
 	var wsurl = Socket.wsurl(window.location.toString());
+	//var wsurl = Socket.wsurl("http://wd.9atom.org/9wd.html");
 	var webdraw = elem("webdraw");
 
 	basetime = Date.now();
@@ -39,13 +40,13 @@
 	Draw9p.imgnames["webdraw"] = Draw9p.RootImage();
 	Draw9p.label = "webdraw".toUTF8Array();
 
-	addevent(webdraw, "mousedown", function(e){
+	setevent(webdraw, "mousedown", function(e){
 		return mouse.handlebutton(e, 1);
 	});
-	addevent(webdraw, "mouseup", function(e){
+	setevent(webdraw, "mouseup", function(e){
 		return mouse.handlebutton(e, 0);
 	});
-	addevent(webdraw, "mousemove", function(e){
+	setevent(webdraw, "mousemove", function(e){
 		return mouse.handlemove(e);
 	});
 	setevent(window, "keydown", function(e){