Xi: add support for input device properties.

Basically just copied from randr properties, with minor changes only.
Each device supports arbitrary properties that can be modified by clients.
Modifications to the properties are passed to the driver (if applicable) and
can then affect the configuration of the device.

Note that device properties are limited to a specific device. A property set
on a slave device does not migrate to the master.

include/inputstr.h

@@ -335,6 +335,38 @@ typedef struct {
 
 } SpriteRec, *SpritePtr;
 
+/* Device properties */
+typedef struct _XIPropertyValue
+{
+    Atom                type;           /* ignored by server */
+    short               format;         /* format of data for swapping - 8,16,32 */
+    long                size;           /* size of data in (format/8) bytes */
+    pointer             data;           /* private to client */
+} XIPropertyValueRec;
+
+typedef struct _XIProperty
+{
+    struct _XIProperty   *next;
+    Atom                  propertyName;
+    Bool                  is_pending;
+    Bool                  range;
+    Bool                  immutable;
+
+    int                   num_valid;
+    INT32                 *valid_values;
+    XIPropertyValueRec    current,
+                          pending;
+} XIPropertyRec;
+
+typedef XIPropertyRec      *XIPropertyPtr;
+typedef XIPropertyValueRec *XIPropertyValuePtr;
+
+typedef Bool (*XISetDevicePropertyProcPtr) (DeviceIntPtr dev,
+                                            Atom property,
+                                            XIPropertyValuePtr prop);
+typedef Bool (*XIGetDevicePropertyProcPtr) (DeviceIntPtr dev,
+                                            Atom property);
+
 /* states for devices */
 
 #define NOT_GRABBED		0
@@ -347,8 +379,9 @@ typedef struct {
 #define FROZEN_WITH_EVENT	6
 #define THAW_OTHERS		7
 
+
 typedef struct _GrabInfoRec {
-    TimeStamp	    grabTime;           
+    TimeStamp	    grabTime;
     Bool            fromPassiveGrab;    /* true if from passive grab */
     Bool            implicitGrab;       /* implicit from ButtonPress */
     GrabRec         activeGrab;
@@ -431,6 +464,12 @@ typedef struct _DeviceIntRec {
         int             valuators[MAX_VALUATORS];
         int             numValuators;
     } last;
+
+    /* Input device property handling */
+    XIPropertyPtr               properties;
+    Bool                        pendingProperties;
+    XISetDevicePropertyProcPtr  SetProperty;
+    XIGetDevicePropertyProcPtr  GetProperty;
 } DeviceIntRec;
 
 typedef struct {