Fred: change unit proxy variable names, to indicate that they are proxy tables
Fred: get rid of zonedata.zone table

It was only used in one place any more, and zonedata.zone_map serves
the purpose just as well or better.
Rename reset_vars CA to reset_vars_turn

to indicate that this only gets done once at the beginning of each
turn, as opposed to reset_vars_move (to be added next) that needs to be
done before each move.
Fred: new CA reset_vars_move

This sets the gamedata and move_cache tables before each move, so that
they can be used by all CAs.
Fred: new CA clear_self_data

This clears the self.data at the end of each turn.  This is done in
order to reduce the amount of data carried along by the AI and, more
importantly, to avoid potential corruption of savefiles.
Fred: remove most content from reset_vars_turn CA

It’s not needed any more.
Fred: minor code simplification of beginning of turn CAs
Fred: move stats CA to be done after reset_vars_move CA

So that it can make use of the gamedata table.  It’s faster that  way.
Fred stats CA: use gamedata table

It’s faster than reaquiring the information.  Also, change the output
format.
Fred full_offensive(): use gamedata table

rather than recalculating unit information
CA debugger: set up gamedata table before CA evaluation

This is now needed with the new CA structure in Fred.
Fix typo in a comment
CA debugger: remove self.data reset/show menu options

They serve no purpose any more with the new CA structure.