fixed a crash related to parsing a non-JSON error from a response string; fixed issue with callbacks being fired after a request has been cancelled; fixed leak of resourcePath in RKRequestTTModel; fixed issue with autoreleasepool being drained before background thread objects have been transferred to the callback method; fixed issues with mutating the requestqueue array during enumeration while performing bulk cancels; added additional logging that has been helpful in tracking down many of these crashes (to be removed prior to merge to master)

Code/ObjectMapping/RKObjectMapper.m

@@ -104,7 +104,13 @@ static const NSString* kRKModelMapperMappingFormatParserKey = @"RKMappingFormatP
 	}
 	
 	NSLog(@"Began parse...");
-	id result = [parser objectFromString:string];
+	id result = nil;
+	@try {
+		result = [parser objectFromString:string];
+	}
+	@catch (NSException* e) {
+		NSLog(@"[RestKit] RKObjectMapper:parseString: Exception (%@) parsing error from string: %@", [e reason], string);
+	}
 	NSLog(@"Finished parse...");
 	return result;
 }