Refactoring in plugin properties to group the properties and methods in the abstract.

Signed-off-by: Hugues Peccatte <hugues.peccatte@gmail.com>
Fix factorizing.

Signed-off-by: Hugues Peccatte <hugues.peccatte@gmail.com>
Merge pull request #805 from Tithugues/refactoringPluginProperties

Factorizing properties and methods of plugin properties in the abstract.