Some apps issues

[German Arias]

Some apps issues. I don't know if these are GNUstep's bugs or if the 
apps need changes.

1) In ProjectCenter in the panel to quit. If you hit TAB to select the 
Quit button, and hit ENTER, ProjectCenter don't quit.

2) LaternaMagica can't display images (only in fullscreen mode)

3) Mplayer can't play music.

4) Yap can't display PDF files. Just display the images in the file.