Remove hard coded admin account.

This isn't needed anymore since we can connect through a local socket
instead if we need admin rights.
Enable persistence of account entities.

This is now on by default whenever the persistence is also enabled. It's
not clear why it wasn't on before though.
As a result Account has also been changed to be able to report whether
it should be persisted or not.
Added goal for clearing focus.

This is useful when we need to forget our current focus and move on.
Don't focus on things we've already discovered.

Also forget these after a while.
This makes sure that this goal doesn't result in the character getting
stuck on one thing. If used with the clear_focus goal the character can
instead move on to other things, and then return to the same thing after
a while after it's "forgotten".
Added a "move me near" goal.

This goal will move a character close to something, and then keep the
character within a certain distance of this thing.
This is useful when you want the character to get close to something,
but then search for something else within the vicinity.
Improve plant_seeds goal.

The NPC will now move between the sources and look for seeds.
Restrict import.
Added goal of spotting in area.
Only search in area when planting.
Improve debug logging.
Fixed bug which prevented fruits from forming.

The semantics of getAttrType was changed to C style return values, so
that you need to check for "0" for success. These calls seems to never
have been properly changed, resulting in fruits never being dropped.
Make clear that this code isn't used.

All tree code is now handle by Plant.cpp. However, this file is kept as
reference (it's of course still in Git, but people tend to never look
for it there if it's removed).
Allow range to be specified in plant seed goal.