Delete duplicated pairs in one time.

eg ```|``` {{|}} [[|]]

plugin/auto-pairs.vim

@@ -142,7 +142,7 @@ function! AutoPairsInsert(key)
     let pprev_char = line[col('.')-3]
     if pprev_char == open && prev_char == open
       " Double pair found
-      return a:key."\<CR>".repeat(a:key,3)."\<Up>\<ESC>o"
+      return repeat(a:key, 4) . repeat("\<LEFT>", 3)
     end
   end
 
@@ -170,12 +170,35 @@ function! AutoPairsDelete()
     return "\<BS>\<DEL>"
   endif
 
+  " Delete Repeated Pair eg: '''|''' [[|]] {{|}}
+  if has_key(b:AutoPairs, prev_char)
+    let times = 0
+    let p = -1
+    while get(prev_chars, p, '') == prev_char
+      let p = p - 1
+      let times = times + 1
+    endwhile
+
+    let close = b:AutoPairs[prev_char]
+    let left = repeat(prev_char, times)
+    let right = repeat(close, times)
+
+    let before = strpart(line, pos-times, times)
+    let after  = strpart(line, pos, times)
+    if left == before && right == after
+      return repeat("\<BS>\<DEL>", times)
+    end
+  end
+
+
   if has_key(b:AutoPairs, prev_char) 
     let close = b:AutoPairs[prev_char]
     if match(line,'^\s*'.close, col('.')-1) != -1
+      " Delete (|___)
       let space = matchstr(line, '^\s*', col('.')-1)
       return "\<BS>". repeat("\<DEL>", len(space)+1)
     elseif match(line, '^\s*$', col('.')-1) != -1
+      " Delete (|__\n___)
       let nline = getline(line('.')+1)
       if nline =~ '^\s*'.close
         let space = matchstr(nline, '^\s*')