moved word_buffer to maca_common

maca_common/CMakeLists.txt

maca_common/include/word_buffer.h

maca_common/src/word_buffer.c

maca_trans_parser/CMakeLists.txt

maca_trans_parser/src/context.c

maca_trans_parser/src/depset.c

maca_trans_parser/src/maca_trans_parser_mcf2cff.c

maca_trans_parser/src/simple_decoder_tagger.c