Fix desktop files' Exec lines
Review Request #128335 - Created July 1, 2016 and submitted
The KF5 port uses QCommandLineParser which doesn't know the '-caption' parameter. The desktop files need to use '-qwindowtitle' instead.
Run kdf and kwikdisk from the application launcher, they start fine now.
Before they didn't, and the message "Unknown options: c, a, p, t, i, o, n." appeared in .xsession-errors.