Use InputMethodSettingsFragment for IME settings

java/AndroidManifest.xml

java/res/xml/method.xml

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

.../com/android/inputmethod/latin/DebugSettingsActivity.java

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

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

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