Choose level and better output

Hi, This is the first time I use Git, I hope that I'm doing this the right way
I just wanted to add these 2 features to your program

Now you need to specify the resolution level in a new argument, if you want to select the highest resolution avaiable you can choose level 0
Is very useful if you want to download panoramas for wallpapers and you dont want to download a biiiiig image for example

Also I needed to replace a backslash (\) into a slash (/) for making it work on Linux, the problem is that I doesn't know if now will work in Windows, because I dont use Windows

Sorry for my english