- add pathogen.vim (https://github.com/tpope/vim-pathogen)

- add vim-airline (https://github.com/vim-airline/vim-airline)

.vim/bundle/vim-airline/autoload/airline/extensions/undotree.vim

@@ -0,0 +1,27 @@
+" MIT License. Copyright (c) 2013-2016 Bailey Ling.
+" vim: et ts=2 sts=2 sw=2
+
+if !exists(':UndotreeToggle')
+  finish
+endif
+
+function! airline#extensions#undotree#apply(...)
+  if exists('t:undotree')
+    if &ft == 'undotree'
+      if exists('*t:undotree.GetStatusLine')
+        call airline#extensions#apply_left_override('undo', '%{t:undotree.GetStatusLine()}')
+      else
+        call airline#extensions#apply_left_override('undotree', '%f')
+      endif
+    endif
+
+    if &ft == 'diff' && exists('*t:diffpanel.GetStatusLine')
+      call airline#extensions#apply_left_override('diff', '%{t:diffpanel.GetStatusLine()}')
+    endif
+  endif
+endfunction
+
+function! airline#extensions#undotree#init(ext)
+  call a:ext.add_statusline_func('airline#extensions#undotree#apply')
+endfunction
+