Support upload g-code to third-party printers

* wip

* fix cmake warning

* add UI and config options for Moonraker connection

* wip: copy whole print host UI from PS

* add more needed options

* wip 2

* fix string issue on Mac

* wip3

* fix cmake warning

* working
need tweaks

* cleanup

* support thumbnail

* fix DNS resolving issue in Windows

* code clean up

src/libslic3r/utils.cpp

@@ -1106,7 +1106,7 @@ std::string string_printf(const char *format, ...)
 
 std::string header_slic3r_generated()
 {
-	return std::string(SLIC3R_APP_NAME " " SLIC3R_VERSION);
+	return std::string(SLIC3R_APP_NAME "-SoftFever" " " SLIC3R_VERSION);
 }
 
 std::string header_gcodeviewer_generated()