ignore ime keydown event
bug fix: when array is empty, [1..array.length] results [1, 0]; so I should use [0...array.length] in some cases
API to lookup IP location
move URL recognizer and image preview from bbs.smth to bbs.common
resolve IP in bbs
click error message in status bar to upload IP file
check IP file format
prevent duplicate error messages in status bar
quickly display an error in status bar
add info message to status bar when IP file is loaded successfully
prevent default ctrl-w chrome behavior