Added single quote string support to font parser

lib/context2d.js

@@ -39,7 +39,7 @@ var baselines = ['alphabetic', 'top', 'bottom', 'middle', 'ideographic', 'hangin
 var weights = 'normal|bold|bolder|lighter|[1-9]00'
   , styles = 'normal|italic|oblique'
   , units = 'px|pt|pc|in|cm|mm|%'
-  , string = '"([^"]+)"|[\\w-]+';
+  , string = '\'([^\']+)\'|"([^"]+)"|[\\w-]+';
 
 /**
  * Font parser RegExp;

test/canvas.test.js

@@ -76,6 +76,8 @@ module.exports = {
       , { size: 50, unit: 'px', family: '"Helvetica Nueue", sans-serif' }
       , '50px "Helvetica Nueue", "foo bar baz" , sans-serif'
       , { size: 50, unit: 'px', family: '"Helvetica Nueue", "foo bar baz" , sans-serif' }
+      , "50px 'Helvetica Nueue'"
+      , { size: 50, unit: 'px', family: "'Helvetica Nueue'" }
       , 'italic 20px Arial'
       , { size: 20, unit: 'px', style: 'italic', family: 'Arial' }
       , 'oblique 20px Arial'