Don't wipe status buffer

This was to address #105, but the annoyance factor is too high to
justify keeping it.

plugin/fugitive.vim

@@ -1883,7 +1883,10 @@ function! s:BufReadIndex()
       endtry
       set ft=gitcommit
     endif
-    setlocal ro noma nomod noswapfile bufhidden=wipe
+    setlocal ro noma nomod noswapfile
+    if &bufhidden ==# ''
+      setlocal bufhidden=delete
+    endif
     call s:JumpInit()
     nunmap   <buffer>          P
     nunmap   <buffer>          ~