URL Encode State Hash

You'll notice a mild asymmetry in how hash was
saved vs retrieved.

The retrieval was:
    JSON.parse(decodeUrlComponent(hash))

The save was:
    JSON.stringify(hash)

I modified it to:
    JSON.stringify(encodeUrlComponent(hash))

The reason I noticed this is in one of my apps,
I wanted to be able to copy/share a stateful filter URL.

However without the url encoding, those auto-parsers
of URLs were missing the full filter.

TESTING CONDUCTED:
1. Updated the Hash unit tests to both parse the
   encoded string, as well as generate it.

2. Ran "grunt", which has built/tested/jslinted
   the code.

test/test-hash.js

@@ -36,14 +36,17 @@ test('Can update URL hash', function() {
 
     // assert
     deepEqual(location.hash,
-        '#{"page":2,"page_length":4,"col_2":{"flt":">500"}}',
+        '#%7B%22page%22%3A2%2C%22page_length%22%3A4%2C%22'+
+            'col_2%22%3A%7B%22flt%22%3A%22%3E500%22%7D%7D',
         'URL hash updated');
 });
 
 test('Can parse a URL hash', function() {
     // setup
-    var hashStr = '#{"page":2,"page_length":4,"col_2":{"flt":">500"}}';
-
+    // URL-encoded version of:
+    //    #{"page":2,"page_length":4,"col_2":{"flt":">500"}}
+    var hashStr = '#%7B%22page%22%3A2%2C%22page_length%22%3A4'+
+            '%2C%22col_2%22%3A%7B%22flt%22%3A%22%3E500%22%7D%7D'
     // act
     var result = hash.parse(hashStr);