CreateDropDatabaseTest refactored to handle AJAX content

I have refactored the Create/Drop Database test to handle the AJAX
content, it uses waitForElementPresent() method to wait for an ajax
response which should be more reliable than sleep(). Next, I have tried
to use more of cssSelectors rather than xpaths as cssselectors cope up
well with structural changes on the page. Not yet added to
AllSeleniumTests.php, waiting for approval.