Implemented substantial catalog example application covering advanced usage of RestKit:

* Cleaned up remaining warnings about if (self = [super init])
* RKParamsExample - Highlights multi-part uploads
* RKRequestQueueExample - Working with the request queue
* RKBackgroundRequestExample - Examples of using the background policies for backgrounding requests
* RKReachabilityExample - Shows how to work with the reachability observer
* RKRelationshipMappingExample - Shows how to map related objects from JSON into an object graph
* RKCoreDataExample - Shows the basics of using RestKit's Core Data examples

Also rearranged dispatch of RKRequest delegate method for didStartLoad: to ensure requeue callbacks get invoked in a timely manner. refs #62

Code/ObjectMapping/RKRailsRouter.m

@@ -12,7 +12,8 @@
 @implementation RKRailsRouter
 
 - (id)init {
-	if (self = [super init]) {
+    self = [super init];
+	if (self) {
 		_classToModelMappings = [[NSMutableDictionary alloc] init];
 	}