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.
Selenium Create Drop DB Test 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.
Merge remote-tracking branch 'ayushchd/unit_testing_local'

Conflicts:
	test/selenium/PmaSeleniumCreateDropDatabaseTest.php