Remember the source dictionary for each suggestion.

java/src/com/android/inputmethod/latin/BinaryDictionary.java

java/src/com/android/inputmethod/latin/Dictionary.java

...c/com/android/inputmethod/latin/ExpandableDictionary.java

java/src/com/android/inputmethod/latin/SettingsValues.java

java/src/com/android/inputmethod/latin/Suggest.java

java/src/com/android/inputmethod/latin/SuggestedWords.java