Added plug-in information class to extend interruptions and persistence description (will be used in Plugin manager).
Author, supported version fields added to process description. Loaded settings slightly changed, integration with plugin manager.
Change existing persistence and plug-ins to include new extended description.
Change interruption and plug-in to include new extended description.
Plugin Manager added. First version, for now shows only installed and available plugins.
Merge branch 'master' of https://github.com/StevenHouben/ABC.git