Reordered Custom Mission event parameters to be consistent with Firaxis events.
Merge branch 'CustomMissionDLL'
Attempts to solve Horn of Valere CTD (unsuccessful).
Unsuccessful attempt to add Horn Of Valere data to save files by hooking into the existing serialization system.
Serialization and Horn of Valere CTD update.

Initial attempt to hook into Firaxis' serialization and creation of save
files to persist Horn of Valere-related data.

Yet another attempt to solve the intermittent Horn of Valere CTD by
removing the CvPlot* pointer from the HornOfValere class.