Removed setspawn. Changed addspawn.

the index for addspawn is now optional.

these two methods were condensed into one.
Refactored addTimedSpawn() methods.

These methods are no longer overloaded.

method signatures:
public void putTimedSpawn(long index, TimedSpawn s);
public long addTimedSpawn(TimedSpawn s);

addTimedSpawn() now returns the index. This is used by the
ArenaEditorExecutor to display the outcome to the command sender.
Fixed method call.

from addTimedSpawn(long index, TimedSpawn s)

to putTimedSpawn(TimedSpawn s)
BattleArena v3.9.7.13