fixup "make level reflect start of scenario"

we change set_attr to set_attr_dup as gfgtdf pointed out
purge "record_change_controller"

we can use "change_controller" now instead because of the new
network adapter from gfgtdf
fixup scenario transitions

when the host transitions to the next scenario, in some cases he will
send "[start]" before the other clients even have the new scenario cfg
this means that the controller tweaks he send will hit them while they
are in linger mode or something, and the next scenario won't work.

we fixup the download_next_level function on the server side so that
it updates the level config when sending it out to the transitioning
client.

this fixes up commit fb726e0610af42fa815cf340fa68c570b8bef0d3
and bug #21931
update changelog
Merge branch 'master' of https://github.com/wesnoth/wesnoth
Bottleneck Defense Micro AI: code cleanup
Messenger Escort Micro AI: code cleanup
Messenger MAI: fix typo

Sigh.  Intentional typo for testing, forgotten to revert it.
Fix bug #21883: make sure movement animations don't cycle with fog on
remove unneccessary unit moving redraw are invalidation code.
Goto Micro AI: prevent potential conflict between Goto MAIs

If several Goto MAIs are used on the same side and both have
unique_goals=yes set, they previously might have interfered with each
other, one preventing the other from working correctly. Now the “goal
taken” information is saved such that it only applies to the CA by
which it was set.
[micro_ai] tag setup: minor code cleanup
Micro AIs other engines: code cleanup
disable mp::configure in mp transient in networked mp

this was only executed on the host. And it didn't work in networked mp because the other clients didn't expect this, and proceeded to the next scenario immediately.
That's why i disabled it in networked mp.
Fix bug #21316: make subframes within standing animations cycle by default
Merge branch 'master' of https://github.com/wesnoth/wesnoth