campaignd: Clear [feedback] from campaign list response *after* using it

Fixes an attempt to dereference a destroyed config object, causing
undefined behavior.
extend NO_CATCH_AT_GAME_END

NO_CATCH_AT_GAME_END now also disables catching to std::exception and const char*
fix team settings in mp

this was broken in https://github.com/wesnoth/wesnoth/commit/f15eed147afbe69e234ab1aa73efad9a497ee46a where the code 2 lines above was changed but not this line.
Move everything in src/filesystem.hpp into its own namespace

This is a chearry pick by me (gfgtdf) of https://github.com/AI0867/wesnoth/commit/66176b1738c5d813959b4cd01536a7cc246831c3. It differes a lot from the original becasue since there were so much merging conflics i decided to do it mostly from scratch.

Conflicts:
	src/addon/manager.cpp
	src/addon/manager_ui.cpp
	src/campaign_server/campaign_server.cpp
	src/config_cache.cpp
	src/create_engine.cpp
	src/editor/map/context_manager.cpp
	src/editor/map/map_context.cpp
	src/font.cpp
	src/game_config_manager.cpp
	src/gamestatus.cpp
	src/gui/dialogs/editor/custom_tod.cpp
	src/gui/dialogs/lobby/lobby_data.cpp
	src/gui/dialogs/mp_create_game.cpp
	src/gui/widgets/settings.cpp
	src/hotkeys.cpp
	src/image.cpp
	src/multiplayer_lobby.cpp
	src/network.cpp
	src/playcampaign.cpp
	src/preferences.cpp
	src/savegame.cpp
	src/serialization/preprocessor.cpp
	src/tests/main.cpp
	src/wesnoth.cpp
	src/widgets/button.cpp
Rename filesystem::file_name to filesystem::base_name
Remove some unneeded includes

Conflicts:
	src/loadscreen.cpp
Make filesystem.hpp not depend on config.hpp being included first

Conflicts:
	src/filesystem.hpp
Rename file_create_time to file_modified_time, as that's what it does

Conflicts:
	src/savegame.cpp
Remove a comment that is no longer true
Split the parts of filesystem.cpp that don't directly interface with the filesystem off into filesystem_common.cpp

Conflicts:
	src/filesystem.cpp
add filesystem_common.cpp to cmake
Don't try to iterate over things that are not directories
Merge commit 'ecf8f3d55cfd9ebc76e99941270500a5781d7819' into AI-boost_filesystem