Deadzone isn't visible to other applications

[JohnStrunk]

Describe the bug
tilt-wizard sets the deadzone, but the changes don't seem to be visible to other applications.

Steps to reproduce
Steps to reproduce the behavior:

1. Run tilt-wizard
2. Give it a bit to settle
3. Launch an application that reads the same device
4. Note that there is no deadzone in effect

Actual results
tilt-wizard can't set the deadzone

Expected behavior
The deadzone settings should be visible in other applications.

Additional context
Add any other context about the problem here.

[JohnStrunk]

It's not clear whether Windows actually supports this or not. DXTweak says DZ settings aren't saved/preserved, but we don't need long-term, just current setting.

This may be related to not calling IDirectInputJoyConfig8::SendNotify after setting the device calibration.

SendNotify notes:

• Requires header dinputd.h that is not in mingw. Looks like I can grab a copy here: https://github.com/google/sagetv/blob/master/third_party/mingw/dx80/include/dinputd.h
• SendNotify docs: https://docs.microsoft.com/en-us/windows/desktop/api/dinputd/nf-dinputd-idirectinputjoyconfig8-sendnotify
• Example using it: https://github.com/elitak/PPJoy/blob/master/PPJoyCpl/DXUtil.cpp

As a stopgap, we could output the recommended DZ percent as a part of the application output. Looks like the DZ should be: stdev * 4 * 100 / axis_range