Unbundle Keyboard.java to BaseKeyboard.java

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

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

.../com/android/inputmethod/latin/LatinKeyboardBaseView.java

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

...om/android/inputmethod/latin/MiniKeyboardKeyDetector.java

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

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

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