ex_joystick_events: Display joystick name, and of sticks, axes, buttons.

With modifications from me (Peter).
Use Linux input API for joystick driver instead of deprecated joystick API.

Some internals were exported to an internal header file in preparation
for a forthcoming haptics driver.

With significant modifications from me (Peter).
Detect linux/input.h and not linux/joystick.h.

The Linux joystick driver now uses the former and not the latter.
Remove hack to force the Linux event mouse driver to compile on R-Pi.

Now that we detect linux/input.h again (we stopped for a while) it
should not be necessary to force lmseev.c to compile specifically on
Raspberry Pi.