Fix: show error if timeline api used out
Improve: change default tweet count of timeline to 30
May be helpful to avoid timeline api quota being used out
Merge branch 'master' into devtest
Fix: show error hint for messages and replies when api used out

Here May Be Bugs: haven't test what $count will be if the user has only 1
messages or replies.
It might be better to adjust the way we check if result is empty.