Add option "GrabDevice", don't grab the device by default.

We now have the matching code in the server to set the console to RAW mode and
don't need to grab the devices anymore.

This is an updated version of e8534d47c8, which
was reverted in 6dc4199155.
(cherry picked from commit 4912e2aa7f)

src/evdev.h

@@ -57,7 +57,7 @@ typedef struct {
 
 typedef struct {
     const char *device;
-    int kernel24;
+    int grabDevice;         /* grab the event device? */
     int screen;
     int min_x, min_y, max_x, max_y;
     int abs_x, abs_y, old_x, old_y;