title: selenium's find element by xpath getting error where same expression in lxml is ok
body: <p>I have faced this problem for various xpath expressions. The <code>find_element_by_xpath()</code> method of selenium fails whereas lxml for the same expression gives the expected value. For example:</p>
  
  <pre><code>&gt;&gt;&gt; lxml.html.fromstring(br.page_source).xpath('//a[@title="2"]/text()')
  ... ['\n\t\t\t\t\t\t2\n\t\t\t\t\t', '\n\t\t\t\t\t\t2\n\t\t\t\t\t']
  
  &gt;&gt;&gt; br.find_element_by_xpath('//a[@title="2"]/text()')
  ... InvalidSelectorException: Message: {"errorMessage":"The result of the xpath expression \"//a[@title=\"2\"]/text()\" is: [object Text]. It should be an element.","request":{"headers":{"Accept":"application/json","Accept-Encoding":"identity","Connection":"close","Content-Length":"108","Content-Type":"application/json;charset=UTF-8","Host":"127.0.0.1:47455","User-Agent":"Python-urllib/2.7"},"httpVersion":"1.1","method":"POST","post":"{\"using\": \"xpath\", \"sessionId\": \"85546b60-7c8e-11e4-b2ba-2bb5fbee7719\", \"value\": \"//a[@title=\\\"2\\\"]/text()\"}","url":"/element","urlParsed":{"anchor":"","query":"","file":"element","directory":"/","path":"/element","relative":"/element","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/element","queryKey":{},"chunks":["element"]},"urlOriginal":"/session/85546b60-7c8e-11e4-b2ba-2bb5fbee7719/element"}}
  Screenshot: available via screen
  </code></pre>
  
  <p>Why is this happening and how can I correct it?</p>