Fix ast typos and report broken shortcuts

[lasers]

./doc/man/pingus.xml:364: Hold to ast-forward
./doc/man/pingus.6:172:Hold to ast-forward

I found the typo reading the manual. I don't know if I should file another issue because the keyboard shortcuts for this game does not behave the way the manual described. I have no problem playing this game because I was able to remap shortcuts by making a new mode for pingus (using i3wm). With my i3wm pingus mode, I used F to activate fast-forward and space for pausing... so I can leave my left hand on the keyboard... and right hand on the mouse.

Here's what happens when I'm playing Pingus 0.7.6

Pressing A activates armageddon. Backspace does not work.
Pressing S works... Pressing F activates fast-forward (That shouldn't happen?)
Pressing R does not work.

I probably can't test some... like AltReturn, F11, etc... but everything else seems to be working okay. Got a screenshot too. FPS Counter, Toggling mouse grab, etc... all works okay.