Remove LatinKeyboard class

java/src/com/android/inputmethod/keyboard/KeyboardSet.java

...rc/com/android/inputmethod/keyboard/KeyboardSwitcher.java

java/src/com/android/inputmethod/keyboard/LatinKeyboard.java

...c/com/android/inputmethod/keyboard/LatinKeyboardView.java

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

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

...ndroid/inputmethod/latin/suggestions/MoreSuggestions.java

tests/src/com/android/inputmethod/latin/SuggestHelper.java