Handle PrintScreen and SysReq on Windows
This key requires a bit extra care on Windows. We get wildly
different messages depending on if Alt is pressed or not. The symbol
chosen now follows the standard behaviour on X11.
diff --git a/doc/keyboard-test.txt b/doc/keyboard-test.txt
index 2d2b2b6..d59499f 100644
--- a/doc/keyboard-test.txt
+++ b/doc/keyboard-test.txt
@@ -81,6 +81,7 @@
- Insert, Delete, Home, End, PageUp, PageDown
- Arrow keys
- Menu
+ - Alt+PrntScrn sends Sys_Req [Win]
- French layout (AZERTY and inverted shift behaviour for many keys)