[client] x11: change to a more visible "dot" cursor

This change alters the small square dot cursor to a more visible 16x16
cursor for X11. A new option `spice:largeDotCursor` can be set to use an
alternative 32x32 cursor for the vision impaired.

client/displayservers/X11/CMakeLists.txt

@@ -17,6 +17,7 @@ add_library(displayserver_X11 STATIC
   x11.c
   atoms.c
   clipboard.c
+  cursor.c
 
   wm/default.c
   wm/i3.c
@@ -27,6 +28,7 @@ add_definitions(-D GLX_GLXEXT_PROTOTYPES)
 target_link_libraries(displayserver_X11
   PkgConfig::DISPLAYSERVER_X11
   lg_common
+  lg_resources
 )
 
 target_include_directories(displayserver_X11