New simple KExiv2 based interface class to manage KIPI host application...

New simple KExiv2 based interface class to manage KIPI host application metadada settings and Read/Lock files mechanism introduced
with list libkipi API by Marcel, to prevent concurents access to files by kipi-plugins and host application at the same time, through image metadata.
This class must be used everywhere in plugins instead KExiv2 (not yet done).
CCMAIL: kde-imaging@kde.org
CCMAIL: marcel.wiesweg@gmx.de