Update Mapping.xml - fix GamepadButtonsFlags

Change GamepadButtonFlags mapping from type short to int.  This fixes an issue with Y flag being incorrectly mapped to Y = short.MinValue. It should be mapped to Y = 32768. 

Here's the relevant DirectX doc section ..

typedef struct _XINPUT_GAMEPAD {  
WORD  wButtons; 
...}

and this ...
XINPUT_GAMEPAD_X 0x4000
XINPUT_GAMEPAD_Y 0x8000

Author: Gavin-Williams

Source/SharpDX.XInput/Mapping.xml

@@ -94,7 +94,7 @@
     <map enum="XINPUT_CAPS_FLAGS" name="CapabilityFlags" type="short"/>
     <map enum-item="XINPUT_CAPS_(.*)" name-tmp="$1"/>
 
-    <map enum="XINPUT_GAMEPAD_BUTTON_FLAGS" name="GamepadButtonFlags" flags="true" none="true" type="ushort"/>
+    <map enum="XINPUT_GAMEPAD_BUTTON_FLAGS" name="GamepadButtonFlags" flags="true" none="true" type="int"/>
     <map enum-item="XINPUT_GAMEPAD_(.*)" name-tmp="$1"/>
     <map enum-item="XINPUT_GAMEPAD_DPAD_(.*)" name-tmp="D_PAD_$1"/>