S3 bucket listing support and network code refactors.

* Adds support for listing all objects in an S3 bucket.
* Renames a bunch of network related classes (Download->Action)
* Net actions now have static constructors

logic/net/ByteArrayDownload.cpp

@@ -2,7 +2,7 @@
 #include "MultiMC.h"
 #include <logger/QsLog.h>
 
-ByteArrayDownload::ByteArrayDownload(QUrl url) : Download()
+ByteArrayDownload::ByteArrayDownload(QUrl url) : NetAction()
 {
 	m_url = url;
 	m_status = Job_NotStarted;