Ver. 2.0
add status bar with welcome and information of author
Ver. 2.1
add status bar with information of files rows and columns
Ver. 2.2
add status bar with information of file open success
Ver. 2.3
add status bar with information of file save success
Ver. 2.4
add status bar with information of on finding
Ver. 2.5
add status bar with information of file closed