Update KWordquiz handbook to 16.04

proofreading
remove entity package, not used any more
bump date + releaseinfo
fix download path
add missing shortcut
remove commented go-to-menu and obsolete option Rows/Columns
replace Settings + Help menu with link to fundamentals
remove chapter id=faq
remove appendix

new screenshots
comment chapter tutor mode, not yet ported to kf5
REVIEW:127859