activator moved, uses-constraints, no singleton

moved activator to internal non-exported package (no access from outside
the bundle);
uses-constraints inserted;
bundle is no singleton
feature.xml removed
URIUtils readded
dependencies recalculated, informations reworked
dependencies, informations reworked, pmd-feature

dependencies recalculated;
feature-informations reworked;
feature 4.0.1 for pmd-eclipse-plugin embedded
non-existing package removed