Fixed issue #1848: TortoiseGitBlame doesn't scroll to the previously selected line on "Blame previous revision"

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Underline git hash in log message view and jump to that commit when clicking on the hash

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