ensure overridden effectors are invoked (though the "rich" detection done in EntityType for config-keys still should be applied),
and prefer effector definitions from statics over those from methods
display tasks better
be stricter about tags used to mark entity association from tasks (major) -
a big step towards moving away from tasks altogether as most usages now go through BrooklynTasks;
this gives us clarity about which entity is submitting, which is the context, and which is the target (for effectors)

this may have damaged task/entity gc -- there is one failing test i haven't been able to fix (and have marked disabled,
for now, so i could build, but we should fix it asap!) -- EntityExecutionManagerTest.testUnmanagedEntityCanBeGcedEvenIfPreviouslyTagged
tidies for code review in PR #874