Sync with TortoiseSVN

Use unique_ptr and drop logically dead code.

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Drop logically dead code

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Fixed issue #2331: Show prefix log asterisk in Log Dialog

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>