Do not load unneeded packages with map loading

[GunChleoc]

There are some packages that need to be loaded with the map when loading a savegame, but do not need to be loaded when starting a new game or opening a map in the editor.

An attempt to fix was made by putting the compatibility code back in:

https://code.launchpad.net/~widelands-dev/widelands/map_compatibility

A better fix would be not to save or load these packages at all when there is no actual game involved, because they cause compatibility problems.

The following packages have been identified as candidates for not to be included:

log("Writing Flag Data ... ");
log("Writing Road Data ... ");
log("Writing Map Objects ... "); - this is probably needed in editor, or isn't it?
// DATA PACKETS 3 sections here
log("Writing Node Ownership Data ... ");
log("Writing Exploration Data ... ");
log("Writing Players Unseen Data ... ");
log("Writing Scripting Data ... ");
log("Writing Objective Data ... ");

[kaputtnik (franku)]

I am unsure if there are some packages will be needed in future in editor. See https://wl.widelands.org/forum/topic/1703/ regarding loading tribes. So if tribes are loaded as default, there are may several packages which depend on the tribes, aren't there?

[GunChleoc (gunchleoc)]

Only if we have actual tribe objects on the map, like e.g. buildings. Scenarios might also have pre-filled buildings, but that's all done in Lua at the moment.

If we need them in the future, we could work with packet numbers: if packet number > x, load, otherwise don't load.

[GunChleoc (gunchleoc)]

Fixed in build19-rc1.