fix initialization of :TweetVimUserStream

:TweetVimUserStream
による初期化時にフィルターが適用されていないバグを修正しました．
Merge branch 'rhysd-fix/init_of_userstream' into dev
changed default of tweetvim_reconnect_seconds
show direct message to tweetvim buffer
Merge branch 'ompugao-show_direct_message' into dev
improved direct message at userstream
add reply_to_all action.
add keymapping
prevent repeating the same user
Merge branch 'ompugao-reply_to_all' into dev
improved reply to all
improved multi line's favorite action
added buffer_previous_stream action
fixed bufno
improved back to userstream
return when tweetvim is disconnected
Merge pull request #20 from ompugao/return_when_disconnected

s:flush_tweet returns when tweetvim is disconnected
reconnect to userstream at reload action
changed default value that interval seconds to reconnect