[CB08] Create a combiner chain in the word composer.

java/src/com/android/inputmethod/event/CombinerChain.java

java/src/com/android/inputmethod/event/EventDecoderSpec.java

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

.../com/android/inputmethod/latin/inputlogic/InputLogic.java

tools/dicttool/Android.mk