Switch to using uba instead of ub

uba will launch Uzbl for eacy URI on STDIN, so it's easier to link with
saturnin-www or any other command while keeping it simple and unix-y.

Original scenario of opening always just one URI can be easily achieved
using `head -1`.

dotfiles/i3/config

 ### MINE
 bindsym $mod+Return         exec "urxvt"
 bindsym $mod+Shift+Return   exec "xfce4-terminal"
-bindsym $mod+b              exec "ub -1"
-bindsym $mod+Shift+b        exec "saturnin conf -j -S www.ini | saturnin dmenu -l 20 --split = | xargs -r ub -a"
+bindsym $mod+b              exec "saturnin www -1 | head -1 | uba"
+bindsym $mod+Shift+b        exec "saturnin conf -j -S www.ini | saturnin dmenu -l 20 --split = | uba"
 bindsym $mod+c              exec "saturnin clip save"
 bindsym $mod+Shift+c        exec "saturnin clip load"
 bindsym $mod+Shift+f        exec thunar