Update Ladybug_Export Ladybug - .ghuser folder path

"Ladybug Export" component finds default folder for .ghuser files:

UOFolder = "C:\\Users\\" + os.getenv("USERNAME") + "\\AppData\\Roaming\\Grasshopper\\UserObjects\\"

Wind XP does not have the "Roaming" folder. So for Win XP the path is different. Maybe we could try this instead:

UOFolder = gh.GH_ComponentServer.GHUser_AppDataDirectory

Thanks @stgeorges,
Good find! Two minor comments:
1. You probably don't need line 36.
2. Do you want also to update the userObject and send both of them in a single pull request?