BitComet 0.73

- GUI Improved: add the function to scan virus upon download finish
- GUI Improved: add a prompt to scan virus when open executable file
- GUI Improved: add scan virus to task list and file list context menu
- GUI Improved: add scan virus setting page in Preferences dialog
- GUI Improved: add language translate editor dialog to option menu
- GUI Improved: add the function to move task downloded files to corresponding folder when change task catalog
- GUI Improved: add catalog setting to BT task properties dialog
- GUI Improved: add upload/download speed limit settings to advanced page of BT task properties dialog
- GUI Improved: add a option to hide confirm dialog when open BCTP link from IE
- GUI Improved: remove Caps LockNum Lock and ScrollLock status display in main window's status-bar
- GUI Bugfix: fix the bug that the disk available space is displayed error in BT task properties dialog
- GUI Bugfix: fix the bug that the default TCP half-open number setting is too small in Windows2003
- Core Improved: add specific task upload/download speed limit function
- Core Bugfix: fix the bug of high CPU usage when enable upload/download speed limit