Check whether a page already exists before creating a new one

Steps to follow to reproduce:

• create a new page using the browser
• write some content
• save the new page
• create a new page using XWord. The name & space of the page should be the same as in the previous case
• write some different content
• click "Publish document"

Result: The page created with XWord overwrites the page created in the browser.

Suggestion: When creating a new page from XWord there should be a check to see if the page already exists.