implemented basic bayesian filter.
modified interface of XFilter result. Added API to open/close bayes db.
added API to get kvs total sum.
added API to get kvs record number.
implemented KVS APIs and QDBM implementation.
don't normalize case.
drop OTHER_SYMBOL on word separator.
bayes-filter.c: added word-count func.
implemented simple stopword.
Implemented simple word separator.