ISIS-726, ISIS-727: unified commands/auditing.

In addition
- new Hidden(Where.ALL_EXCEPT_STANDALONE_TABLES)
- minor enhancement to ObjectContracts for sorting.
- new IterableExtensions.fold and Closure class
- raise logging levels for some of the noisier Isis classes during bootstrapping
ISIS-541: fixes for contributee associations for hide/disable ...

... on contributed actions.

This is the same stuff as in the contributee actions.