sylfilter: allow multiple file input.
added option to show learning status.
renamed old sylfilter.c to sylfilter-test.c and added new sylfilter.c.
implemented basic bayesian filter.
modified interface of XFilter result. Added API to open/close bayes db.
implemented KVS APIs and QDBM implementation.
return different value for each result
implemented simple stopword.
added a function to read message files.