removed overlay message hiding from "game_started" event as it is already being hidden by A.set_status()
Removed _place_roads_on_map(), added first version of _mapgen__generate_roads().
Moved ObjectPlayer1Destination creations to _mapgen__generate_roads(), road tiles are now generated in larger batches.
_mapgen__generate_roads(): added some comments, starting_points[] now stores target_point id.
Rebased to contain master changes.

Merge branch 'dev-mapgen' of github.com:gheja/untitled13 into dev-mapgen