Cleanup proximity related code

java/res/values-en/additional-proximitychars.xml

java/res/values/additional-proximitychars.xml

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

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

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

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

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

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

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

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

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

...ndroid/inputmethod/latin/suggestions/SuggestionsView.java