move rainbarf to tmux folder

Does not belong in the powerline folder. Also, have discovered that Inconsolata
does not display the following correctly:

▁ ▂ ▃ ▄ ▅ ▆ ▇ █

https://github.com/creaktive/rainbarf/issues/10

This string can be used to see if a font properly supports the usage bars.
As it turns out, Menlo does (using the powerline-patched Meslo works well).

There is still the issue with Menlo where some of the red fonts are raised 1
pixel over the others.

.gitmodules

@@ -13,3 +13,6 @@
 [submodule "powerline/rainbarf"]
   path = powerline/rainbarf
   url = https://github.com/creaktive/rainbarf.git
+[submodule "tmux/rainbarf"]
+	path = tmux/rainbarf
+	url = https://github.com/creaktive/rainbarf.git

tmux/tmux.conf

@@ -117,6 +117,6 @@ set -g status-bg colour234
 set -g status-left-length 90
 set -g status-left '#[fg=colour189,bg=colour55] #S #[fg=colour55,bg=colour233]#(powerline tmux left)'
 set -g status-right-length 90
-set -g status-right '#(powerline tmux right) #(~/dotfiles/powerline/rainbarf/rainbarf --remaining --rgb --width 10)'
+set -g status-right '#(powerline tmux right) #(~/dotfiles/tmux/rainbarf/rainbarf --remaining --rgb --width 10)'
 set -g window-status-format " #[fg=colour244,bg=colour234]#I#F#[fg=colour249]#W "
 set -g window-status-current-format "#[fg=red,bg=red] #[fg=colour231,bg=red]#I #[fg=colour231,bold]#W#[fg=red,bg=red,nobold] "