Game save/restore doesn't preserve current Settler progress

[fire-eggs]

Saving / restoring a game resets any Settler activity (irrigation, mining, etc) to zero.

Settlers.cs, GetStatus and SaveStatus need to restore / save the current settler progress. There is a "Special Moves" unit field in the savefile which is meant to record this [offset 5, according to the format topic in CivFanatics].

NOTE: from code review, needs confirmation.