windowswap: use new tab-aware API if WS is current
windowswap: use new tab-aware API if WS is current

dalguji/vim-airline,chrisbra/vim-airline,tschundler/dotfiles,tschundler/dotfiles,yzhou61/vim-airline,rchicoli/vim-airline,unphased/vim-airline,bling/vim-airline,vim-IDE/vim-airline,tschundler/dotfiles,HarmtH/vim-airline