Add DictEncoder.

...m/android/inputmethod/latin/AbstractDictionaryWriter.java

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

...c/com/android/inputmethod/latin/makedict/DictEncoder.java

...m/android/inputmethod/latin/makedict/Ver3DictEncoder.java

...tmethod/latin/makedict/BinaryDictDecoderEncoderTests.java

...id/inputmethod/latin/makedict/BinaryDictIOUtilsTests.java

...m/android/inputmethod/latin/dicttool/DictionaryMaker.java

...tmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java