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/PrintHost.hpp

@@ -0,0 +1,31 @@
+#ifndef slic3r_PrintHost_hpp_
+#define slic3r_PrintHost_hpp_
+
+#include <string>
+#include <wx/string.h>
+
+
+namespace Slic3r {
+
+
+class DynamicPrintConfig;
+
+class PrintHost
+{
+public:
+
+	virtual bool test(wxString &curl_msg) const = 0;
+	virtual wxString get_test_ok_msg () const = 0;
+	virtual wxString get_test_failed_msg (wxString &msg) const = 0;
+	// Send gcode file to print host, filename is expected to be in UTF-8
+	virtual bool send_gcode(const std::string &filename) const = 0;
+	virtual bool have_auto_discovery() const = 0;
+	virtual bool can_test() const = 0;
+};
+
+
+
+
+}
+
+#endif