Use the default is XDG_CONFIG_HOME is not set
New 'grab_pointer' argument: 'resize_side'

The 'resize' argument is now called 'resize_corner'.
Reuse W
Unify tiled and floating pointer actions

The following 'grab_pointer' arguments are removed: 'move_tiled',
'resize_tiled'. The regular 'move' and 'resize_*' arguments shall be
used instead. The 'fence_grip' parameter is no longer meaningful and
has been removed. Moving and resizing now behaves the same for tiled and
floating windows.
Remove obsolete prototypes
Update TODO
Focus follows pointer rewrite
Update TODO.
Disable motion recording as soon as possible

Also, get_pointed_window needs to lower the motion_recorder
window otherwise xcb_query_pointer will return that window as child
attribute.