filesystem: Make support of browsing into archives optional

The ability to browse, scan and play content in archives can cause problems on low powered/low memory devices.
It's quite common to see reports of a large rar file that causes xbmc to crash with an out-of-memory error when browsing or scanning.
It also can be slow as any archive in the directory is opened and extracted.

Add a settings option to enable this feature and default to disabled on Pi