src/Pure/Tools/plugin.ML
2014-10-13 wenzelm 2014-10-13 tuned signature;
2014-10-13 wenzelm 2014-10-13 clarified load order; tuned signature;
2014-10-13 wenzelm 2014-10-13 support for indirections (defined entries), e.g. relevant for quickcheck and its sub-plugins;
2014-10-13 wenzelm 2014-10-13 support for named plugins for definitional packages;