Improve & Setup

Improve PictureViewer
Setup NewTweetWindow
AccountButton
misc.ThreadProc
SettingWindow and NewTweetWindow

Start a new thread to interact with internet. UI will not be blocked.
Update README.md
Upload image

sina plugin: Upload image
Update README.md
Automatically adjust external window position

Horizontally, put new window right to main window. If there's not enough
space, put it left to main window.
Vertically, put new window to with the same height with main window. If
there's not enough space, let the bottom of new window touch the screen.
IconButton: buble indicator

Set buble to indicate unread message count
Unreads notification
Exception handling

AbstractPlugin.getData: Handle network error
NewTweetWindow: Force user to select at least one account.
ResponseWidget UI constructed

ResponseWidget: comment or repost a tweet
Update README.md
rename parameter id to other names

avoid conflict with built-in function id
Sina plugin decorator

Decorator to handle error code
Sina plugin sendComment
easy_thread

easy_thread: easily create new thread to retrieve data and update UI
after that.
retweet and comment

Can now retweet and comment a tweet
bug fix: config_manager.py

fix crash when conf.ini doesn't exist