Replace parleys version string with KDE Applications version

Summary:
The script updated KDE Application version string now used instead of
Parleys native version string on command line, about dialog and
generator tag in kvtml files.
Implementation is done following the guideline found here:
https://community.kde.org/Guidelines_and_HOWTOs/Application_Versioning

Reviewers: #kde_edu, aacid

Reviewed By: aacid

Subscribers: kde-edu, aacid

Tags: #kde_edu

Differential Revision: https://phabricator.kde.org/D10394