Please describe the problem:
When in fullscreen or slideshow, the preferences set in "Preferences/Viewer" are
no longer applied.
Whatever is selected in "Preferences/Viewer", fullscreen/slideshows uses just
"Fit to window if larger".
In the 2.6 series it those preferences were used for both Viewer and
fullscreen/slideshow.
If in 2.7 we are using them only for "viewer", then we need a separate tab for
fullscreen/slideshow view preferences.

Steps to reproduce:
1. Select "set image to actual size" or anything else except "Fit to window if
larger"
2. Start slideshow or enter fullscreen.



Actual results:
The image is modified to "Fit to window if larger"

Expected results:
Follow the preference set in "Preferences/Viewer"

Does this happen every time?
yes

Other information: