Input: rename DeviceIntRec->isMaster to ->type.

isMaster is not enough as long as we differ between master pointers and
keyboard. With flexible device classes, the usual checks for whether a
master device is a pointer (currently check for ->button, ->valuators or
->key) do not work as an SD may post an event through a master and mess this
check up.

Example, a device with valuators but no buttons would remove the button
class from the VCP and thus result in the
IsPointerDevice(inputInfo.pointer) == FALSE.

This will become worse in the future when new device classes are introduced
that aren't provided in the current system (e.g. a switch class).

This patch replaces isMaster with "type", one of SLAVE, MASTER_POINTER and
MASTER_KEYBOARD. All checks for dev->isMaster are replaced with an
IsMaster(dev).

dix/inpututils.c

@@ -268,9 +268,9 @@ change_modmap(ClientPtr client, DeviceIntPtr dev, KeyCode *modkeymap,
     do_modmap_change(client, dev, modmap);
 
     /* Change any attached masters/slaves. */
-    if (dev->isMaster) {
+    if (IsMaster(dev)) {
         for (tmp = inputInfo.devices; tmp; tmp = tmp->next) {
-            if (!tmp->isMaster && tmp->u.master == dev)
+            if (!IsMaster(tmp) && tmp->u.master == dev)
                 if (check_modmap_change_slave(client, dev, tmp, modmap))
                     do_modmap_change(client, tmp, modmap);
         }