[mozilla#347] Merges context fix and adds multi-context testing

plugins/flickr/popcorn.flickr.js

@@ -84,7 +84,7 @@
           uri += "tags="+tags+"&";
         }
 
-        uri += "lang=en-us&format=json&jsoncallback=?";
+        uri += "lang=en-us&format=json&jsoncallback=flickr";
 
         Popcorn.xhr.getJSONP( uri, function( data ) {
         //$.getJSON( uri, function( data ) {

popcorn.js

@@ -1000,17 +1000,16 @@
 
     callback = params.length ? ( parts[1] ? parts[1] : parts[0]  ) : "jsonp";    
 
-
     if ( !paramStr && !isScript ) {
       url += "?callback=" + callback;
     }
 
-
     if ( callback && !isScript ) {
 
       //  If a callback name already exists...
       if ( !!window[ callback ] ) {
-        //  Create a unique new callback name
+
+        //  Create a new unique callback name
         callback = Popcorn.guid( callback );
       }
 
@@ -1041,12 +1040,12 @@
       //  Executing for JSONP requests
       if ( fired || /loaded|complete/.test( script.readyState ) ) {
 
-        // cleanup in here
+        //  Garbage collect the callback
         delete window[ callback ];
 
+        //  Garbage collect the script resource
         head.removeChild( script );
       }
-
     };  
 
     head.insertBefore( script, head.firstChild );

test/data/jsonp.php

@@ -0,0 +1,14 @@
+<?php
+
+$callback = $_REQUEST['callback'];
+
+if ( !$callback ) {
+
+  $callback = explode( "?", end( explode( "/", $_SERVER['REQUEST_URI']) ) );
+  $callback = $callback[0];
+
+}
+
+echo $callback . '({ "data": {"lang": "en", "length": 25} });';
+
+?>