fix powerline losing colour after sourcing vimrc

vim/vimrc

@@ -63,6 +63,9 @@ if has("autocmd")
 
     " Source the vimrc file after saving it
     autocmd bufwritepost .vimrc source $MYVIMRC
+    autocmd bufwritepost .vimrc call Pl#Load()
+    " Reload Powerline colours after source
+    " https://github.com/Lokaltog/vim-powerline/issues/28
 
     " if the last window is NERDTree, then close Vim
     "autocmd bufenter * if (winnr("$") == 1 && exists("b:NERDTreeType") && b:NERDTreeType == "primary") | q | endif