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/ForgeXzDownload.cpp

@@ -8,7 +8,7 @@
 #include <logger/QsLog.h>
 
 ForgeXzDownload::ForgeXzDownload(QUrl url, MetaEntryPtr entry)
-	: Download()
+	: NetAction()
 {
 	QString urlstr = url.toString();
 	urlstr.append(".pack.xz");