OpenUserDataFolder makes it if needed

If you open your user data folder to put stuff in it, that means
you want it, so if it isn't there, we should create it.

Closes surge-synthesizer#1323

src/common/gui/SurgeGUIEditor.cpp

@@ -36,6 +36,16 @@
 #include "vstgui/lib/platform/platform_x11.h"
 #include "vstgui/lib/platform/linux/x11platform.h"
 
+#if LINUX
+#include <experimental/filesystem>
+#elif MAC || TARGET_RACK
+#include <filesystem.h>
+#else
+#include <filesystem>
+#endif
+
+namespace fs = std::experimental::filesystem;
+
 #if LINUX && TARGET_LV2
 namespace SurgeLv2
 {
@@ -3081,6 +3091,8 @@ void SurgeGUIEditor::showSettingsMenu(CRect &menuRect)
 
 
     addCallbackMenu(dataSubMenu, "Open User Data Folder", [this]() {
+       // make it if it isn't there
+       fs::create_directories(this->synth->storage.userDataPath);
        Surge::UserInteractions::openFolderInFileBrowser(this->synth->storage.userDataPath);
     });
     did++;