Minor corrections to Impres Guide 7.4

Hi @PeeWee

I found typos in the chapter names, you may want to fix (or let me know if you want me to do)

IG7405-ManagingGraohicObjects
IG7409-SlideShowsPhotoAldums

Cheers
Olivier

Corrections made to filenames

Peter Schofield
psauthor@gmail.com
Technical Writer, LO Documentation Team