Key short-cuts

Anywhere :

'Undo' to start the preview.
For registered user '[Shift]Undo' to start a precalcuated preview.

In the viewer :

'Enter' to Play/Pause
'0' to stop
'(' to go to the previous picture
'[shift](' to go to the previous 10 picture
')' to go to the next picture
'[shift])' to go to the next 10 picture
