Use window-numbering-assign-func for neotree number
Use window-numbering-assign-func for neotree number

Using window-numbering-assign is simpler and more reliable than using
window-numbering-before-hook and neo-after-create-hook.

tsonntag/dotemacs,tsonntag/dotemacs,tsonntag/dotemacs,tsonntag/dotemacs