update kontact docbook to kf5, delete kontact-admin docbook + import valid info to kontact docbook

proofread + update
remove kappname + package, not used in kf5
bump date + releaseinfo
remove sect shortcuts, it is in fundamentals
remove obsolete hompage link
fix command line arguments
new screenshots
import valid content from kontact-admin docbook + delete kontact-admin docbook
REVIEW:129629
REVIEW:129561