Added possibility for upload to Duet

Further changes:
- Added new configuration option Host Type
- Added abstract base class for future printer hosts
- Moved location of upload dialog (also made it a little bit more configureable)
- added possibility to send file via postfield instead a new frame

xs/src/slic3r/Utils/PrintHostFactory.cpp

@@ -0,0 +1,21 @@
+#include "PrintHostFactory.hpp"
+#include "OctoPrint.hpp"
+#include "Duet.hpp"
+
+#include "libslic3r/PrintConfig.hpp"
+
+namespace Slic3r {
+
+
+PrintHost * PrintHostFactory::get_print_host(DynamicPrintConfig *config)
+{
+	PrintHostType kind = config->option<ConfigOptionEnum<PrintHostType>>("host_type")->value;
+	if (kind == htOctoPrint) {
+		return new OctoPrint(config);
+	} else if (kind == htDuet) {
+		return new Duet(config);
+	}
+	return NULL;
+}
+
+}