Do not say Filter by Bug-IDs if bug ID for project is not set

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
Introduce ALT+SHIFT for navigating the history w/o selecting and make ALT select the commits

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Add jump to w/o selecting a commit to find dialog

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Bind mouse back/forward buttons for navigating the history

Signed-off-by: David Ellsworth <davide.by.zero@gmail.com>
Prevent possible endless going back

Assume history is A B C A.
go back will never stop => C B A C B A...

Signed-off-by: Yue Lin Ho <b8732003@student.nsysu.edu.tw>
Signed-off-by: Sven Strickroth <email@cs-ware.de>