BUG: 160990
BUG: 160990

When scrolling one page, use 80% of the available height of the current
view (not the height of the complete widget including the message structure viewer)

svn path=/trunk/KDE/kdepim/; revision=1017452

lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi