This fixes the following bugs for the autocomplete suggestions:

• in directory mode, too many terms were displayed (e.g. always a pair of the input and the suggestion term) because of wrong XML parsing of the response (whitespace textnode was interpreted too).
• in "check terms for results" nothing was returned due to a wrong query format.
• the jquery autocomplete widget did not recognise the input fields due to class definition.
• some CSS code was added to create a dropdown with non-transparent background.