indent phrase_index.cpp
add const modifiers
fixes a typo
add mask out test cases to chewing/pharse table
add mask out test cases to ngram
add test cases for pinyin_mask_out
write pinyin_get_chewing/pinyin_string
add comments
write pinyin_token_*
add comments
remove pinyin_clear_constraint*
remove pinyin_translate_token
remove pinyin_get_pinyins_from_token
fixes pinyin_translate_token
a safe guard for chewing
fixes autogen.sh
clean up configure.ac
code re-factor
write genpinyins.py
code re-factor