Add options where data and conf stored

[xdaniel9]

In some cases the app is not installed in program files but still want different users to use, for example, installed in C:\Users\Public then the conf and cache should be located in appdata or localappdata folder

[kanryu]

From the beginning of development, we have believed that QuickViewer should be a portable application, and storing data in Public or AppData and polluting the user environment goes against our policy.
If you want to carry it around on a USB memory stick, start it up on any computer whenever you like, and be able to remove it when it's no longer needed, data shouldn't be stored in the user area.
The exception to this is when installing with Chocolatey, which is an annoying package tool that installs to a special folder and cannot save data in the current directory. In this case, the behavior changes so that data is saved under AppData.