Some mouses have additional buttons which can be conveniently used for window
move/resize operations. Buttons 4-7 are skipped since they represent scroll
events.

Unlike buttons 1-3 these two can be used solely for window resize/movement
actions and so do not require modifier.

This prevents pointer being centered on a node when the option is configured.
It helps in case when xbanish only enables pointer following focus when the pointer
is invisible. Which is needed to prevent 'caging' pointer on some modal dialog
windows.

Split node vertically only when width exceed height of node hvsplit_ratio times.

Since gcc 10 compiler defaults to -fno-common. In bspwm it is fixed in master.
Set flag explicitly to avoid pulling in changes from master.