Add keybindings to navigate the list of log entries

[kgrossjo]

This is awesome stuff!

May I suggest to add some keybindings? Currently, I can click one of the lines in the log graph and I get some information about that commit in the bottom part of the window.

WIBNI I could navigate using the keyboard, too? Maybe some kind of cursor, then allow j/k for navigation, and Enter selects the current line like a click does.

[nikhilkalige]

@kgrossjo I have created this feature.. will push for the next release