External diff tool support
It would be great if gui diff tools like meld or diffuse could be launched right from gitg. For example, diffuse has following options:
( -c | --commit ) <rev> File revisions <rev-1> and <rev>
( -m | --modified ) Create a new tab for each modified file
( -r | --revision ) <rev> File revision <rev>
Second option could be used for current changes entry or at stage tab.