Fixed a bug when the planet and fleet lists where modified while being read and throwing an exception, by adding a property to call ToList first on the list.
Fixed a bug when the planet and fleet lists where modified while being read and throwing an exception, by adding a property to call ToList first on the list.

aaron-lillywhite/planet-wars-competition,reichlew/planet-wars-competition,aaron-lillywhite/planet-wars-competition,reichlew/planet-wars-competition,reichlew/planet-wars-competition,aaron-lillywhite/planet-wars-competition