Arrow keys for frame for frame forwarding/rewinding#3851

Hello Medal,

I did it for 100th time, I used left arrow key to rewind 1 frame of my clip just to be reset back to the beginning of a clip. I am confident that almost noone uses left arrow key to go to the start of the clip but uses it to expect to rewind couple seconds.
I would suggest that by default arrow keys would forward/rewind set amount of seconds and for example combination of shift+arrow key would forward/rewind 1 frame.

Best regards
nomenyan