Database History
----------------

There's experimental support for looking at the transaction log of the entire
database.

    >>> browser = Browser(url)
    >>> browser.getLink('help').click()
    >>> browser.getLink('latest 5 transactions').click()

    >>> printCSSPath(browser, 'title')
    <title> ZODB Transactions, page 1</title>

Sometimes it's slow so we can ask for fast mode that lists only object OIDs,
but no types/paths/reprs

    >>> url = browser.url
    >>> browser.open(url + '?fast=1')
    >>> printCSSPath(browser, 'title')
    <title> ZODB Transactions, page 1</title>

    >>> printCSSPath(browser, '.diff li')  # doctest: +ELLIPSIS
    <li>
      <a href="@@zodbbrowser?oid=XX&amp;tid=XXXXXXXXXXXXXXXXXX">
        0x4
      </a>
      <a href="@@zodbbrowser?oid=XX&amp;tid=XXXXXXXXXXXXXXXXXX">
        (view object)
      </a>
    </li>
    ...

This mode kicks in automatically when rendering takes more than 10 seconds,
if you'd rather wait to see the full information, you can ask for that too

    >>> browser.open(url + '?full=1')
    >>> printCSSPath(browser, '.diff li')  # doctest: +ELLIPSIS
    <li>
      <a href="@@zodbbrowser?oid=XX&amp;tid=XXXXXXXXXXXXXXXXXX">
        0xXX
      </a>
      &lt;class 'BTrees.OOBTree.OOBTree'&gt;
      <a href="@@zodbbrowser?oid=XX&amp;tid=XXXXXXXXXXXXXXXXXX"></a>
      <a class="objlink" href="@@zodbbrowser?oid=XX&amp;tid=XXXXXXXXXXXXXXXXXX">
        &lt;BTrees.OOBTree.OOBTree with oid XX&gt; (5 items)
      </a>
    </li>
    ...
