Revert external/hidapi to an older commit

The previous update to the latest hidapi upstream introduced changes that
break HID Feature reports on Windows. This fix sets the hidapi submodule to
the commit preceeding the problematic one.

For a description of the problem see hidapi's issue list:

  https://github.com/signal11/hidapi/issues/192
Add links to EXT device documentation
Add detection for Sharp Shooter's pump action
Fix EXT device report buffer size

This makes the EXT device support work on Windows.
Add missing line breaks in debug output