Some Micro AIs save information in unit variables. Examples are the patrol and messenger AIs, which save the next waypoint for a unit. This needs to be done as a synced command, so that the information is not lost when continuing a game from a replay.
The main reason for doing this, besides simplifying the code, is to avoid using the WML table dump __cfg, which is slow. This includes a change of the format in which the variables are stored, but since these are internal Micro AI utility functions, that does not matter.
(cherry-picked from commit 133568efe6851944f0b9ddaaf75ccaff0cad6a4d)
These provide a simple and consistent way of storing variables inside
[micro_ai] tags in unit variables. This is needed for fixing a bug
with variables stored in units from a previous MAI causing problems
with a subsequent MAI.
