Lock MP settings by default if "force_lock_settings" was set.

Previously, "Use map settings" along with "force_use_map_settings" were used for this.
Revert "Added "controller_lock=no" for multiplayer maps."

Reverting since "controller_lock" will be set to "no" by default.

This reverts commit 6e337de3780870ef024348425cca611f3981c8ac.
Added "force_lock_settings" attribute to LoW.

"force_use_map_settings" was removed since it's replaced by the
attribute mentioned above.
Updated changelog.