add sess_match_ip and sess_match_useragent check.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
remove default array.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
add private config variable and check initialize session.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
update last activity time after checking expire time.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
Merge pull request #8 from appleboy/develop

Support some feature