[Issue #465] Enforcing non-nil path constraint, and making it so that path is relative to the path of the client baseURL

[Issue #465] Providing additional explanation about how to manage the lifecycle of enqueued operations

AFNetworking/AFHTTPClient.h

@@ -300,7 +300,9 @@ typedef enum {
  Cancels all operations in the HTTP client's operation queue whose URLs match the specified HTTP method and path.
  
  @param method The HTTP method to match for the cancelled requests, such as `GET`, `POST`, `PUT`, or `DELETE`. If `nil`, all request operations with URLs matching the path will be cancelled. 
- @param path The path to match for the cancelled requests.
+ @param path The path appended to the HTTP client base URL to match against the cancelled requests. This parameter must not be `nil`.
+ 
+ @discussion This method only cancels `AFHTTPRequestOperations` whose request URL matches the HTTP client base URL with the path appended. For complete control over the lifecycle of enqueued operations, you can access the `operationQueue` property directly, which allows you to, for instance, cancel operations filtered by a predicate, or simply use `-cancelAllRequests`. Note that the operation queue may include non-HTTP operations, so be sure to check the type before attempting to directly introspect an operation's `request` property.
  */
 - (void)cancelAllHTTPOperationsWithMethod:(NSString *)method path:(NSString *)path;
 

AFNetworking/AFHTTPClient.m

@@ -525,13 +525,22 @@ static void AFNetworkReachabilityReleaseCallback(const void *info) {}
     [self.operationQueue addOperation:operation];
 }
 
-- (void)cancelAllHTTPOperationsWithMethod:(NSString *)method path:(NSString *)path {
+- (void)cancelAllHTTPOperationsWithMethod:(NSString *)method
+                                     path:(NSString *)path
+{
+    NSCParameterAssert(path);
+    
+    NSString *URLStringToMatched = [[[self requestWithMethod:(method ?: @"GET") path:path parameters:nil] URL] absoluteString];
+    
     for (NSOperation *operation in [self.operationQueue operations]) {
         if (![operation isKindOfClass:[AFHTTPRequestOperation class]]) {
             continue;
         }
         
-        if ((!method || [method isEqualToString:[[(AFHTTPRequestOperation *)operation request] HTTPMethod]]) && [path isEqualToString:[[[(AFHTTPRequestOperation *)operation request] URL] path]]) {
+        BOOL hasMatchingMethod = !method || [method isEqualToString:[[(AFHTTPRequestOperation *)operation request] HTTPMethod]];
+        BOOL hasMatchingURL = [[[[(AFHTTPRequestOperation *)operation request] URL] absoluteString] isEqualToString:URLStringToMatched];
+        
+        if (hasMatchingMethod && hasMatchingURL) {
             [operation cancel];
         }
     }