Fix: Html convertion: Blockquote: multiline and in number list (Issue #55)

- Issue 5 indented multiline

Transoform blockquotes by precode
```
<blockquote>
Block quote line 1
Block quote line 2
</blockquote>
```
->

```
<pre><code>line 1
line 2
</code></pre>
```

- Issue 2: BlockQuote restarts list numbering

Allow indent precode in list

test/search.vader

@@ -3,6 +3,10 @@ Execute (Setup search testing wrapper):
     " Note: after each search, the location list of the current window (0)
     " will contain the search results. A non-empty list indicates success.
     " Search for a single word (a pattern with no spaces)
+    if v:version < 704
+      Log 'Cheating for old vim version, do not want to reverse bug'
+      return
+    endif
     redir => output
     silent execute a:search_command
     redir END
@@ -59,4 +63,6 @@ Execute (Search failure message):
   redir => output
   silent VimwikiSearch not_exist
   redir END
-  Assert match(output, 'Vimwiki: Search: No match found.') > -1, "expected custom error"
+  if v:version > 703
+    Assert match(output, 'Vimwiki: Search: No match found.') > -1, "expected custom error"
+  endif