+CHAR-AT = '<char-at>' MARKERTERM '</char-at>'
+ => <integer>C</integer>, where C is the character in the preedit text
+ or the surrounding text at the postion specified by MARKERTERM.
+KEY-COUNT = '<key-count/>'
+ => <integer>N</integer>, where N is the number of currently handled keys
+SURROUNDING-TEXT-FLAG = '<surrounding-text-flag/>'
+ => <integer>1</integer> if surrounding text handling is supported
+ or <integer>0</integer> if not.