added Kinetic level pixelRatio property that can be used to override the detected pixel ratio. Also fixed up a pixel ratio related test for FF. added Kinetic.UA for user agent detection

src/Canvas.js

@@ -34,7 +34,7 @@
         init: function(config) {
             config = config || {};
 
-            var pixelRatio = config.pixelRatio || _pixelRatio;
+            var pixelRatio = config.pixelRatio || Kinetic.pixelRatio || _pixelRatio;
 
             this.pixelRatio = pixelRatio;
             this._canvas = document.createElement('canvas');

src/Global.js

@@ -47,6 +47,7 @@ var Kinetic = {};
         enableTrace: false,
         traceArrMax: 100,
         dblClickWindow: 400,
+        pixelRatio: undefined,
 
         /**
          * @namespace Filters

src/Util.js

@@ -84,10 +84,7 @@
             })(n);
         }
     };
-})();
 
-
-(function() {
     /*
     * Last updated November 2011
     * By Simon Sarris
@@ -255,10 +252,25 @@
             this.translate(xt, yt);
         }
     };
-})();
 
+    /*
+    * jQuery UA
+    */
+    Kinetic.UA = (function() {
+        var ua = navigator.userAgent.toLowerCase(),
+            match = /(chrome)[ \/]([\w.]+)/.exec( ua ) ||
+            /(webkit)[ \/]([\w.]+)/.exec( ua ) ||
+            /(opera)(?:.*version|)[ \/]([\w.]+)/.exec( ua ) ||
+            /(msie) ([\w.]+)/.exec( ua ) ||
+            ua.indexOf("compatible") < 0 && /(mozilla)(?:.*? rv:([\w.]+)|)/.exec( ua ) ||
+            [];
+
+        return {
+            browser: match[ 1 ] || '',
+            version: match[ 2 ] || '0'
+        };
+    })();
 
-(function() {
     // CONSTANTS
     var CANVAS = 'canvas',
         CONTEXT_2D = '2d',

test/runner.js

@@ -3,6 +3,8 @@ var assert = chai.assert,
     kineticContainer = document.getElementById('kinetic-container');
 
 Kinetic.enableTrace = true;
+// make sure pixel ratio is 1 or else the tests will fail on devices with retina display
+Kinetic.pixelRatio = 1;
 
 function addStage() {
   var container = document.createElement('div'),

test/unit/Layer-test.js

@@ -21,7 +21,14 @@ suite('Layer', function() {
         var style = layer.getCanvas()._canvas.style;
 
         assert.equal(style.position, 'absolute', 'canvas position style should be absolute');
-        assert.equal(style.border, '0px', 'canvas border style should be 0px');
+
+        if (Kinetic.UA.browser === 'mozilla') {
+          assert.equal(style.border, '0px none', 'canvas border style should be 0px');
+        }
+        else {
+          assert.equal(style.border, '0px', 'canvas border style should be 0px');
+        }
+        
         assert.equal(style.margin, '0px', 'canvas margin style should be 0px');
         assert.equal(style.padding, '0px', 'canvas padding style should be 0px');
         assert.equal(style.backgroundColor, 'transparent', 'canvas backgroundColor style should be transparent');