function! HideIgnoredByGit(...)
  return substitute(substitute(system('git ls-files --other --ignored --exclude-standard --directory'), '\n', ',', 'g'), ',$', '', '')
endfunction

" let g:netrw_keepdir=0
let g:netrw_altv=1          " split window to the right
let g:netrw_liststyle=3     " tree style listing
let g:netrw_list_hide=HideIgnoredByGit() 
let g:netrw_winsize = 30