Moved StoredVessel and LaunchedVessel to their own file. Added PackedConstruct for in-editor vessel storage.
Added mass calculation.
Added mass display to vessel info
Generalized VesselPack. Added Save-Load methods.
Added ability to add-remove vessels to a hangar in Editor.

Alsow:
	* Changed FlightScreenMessager into SceenMessager that works in
every scene.
Added VesselWrapper.cs
Fixed VesselsPack.Load. Added VesselWaiter base class for use in coroutines.
Turned store_constructs into coroutine. Working InEditor hangar storage solution.
Updated tasks
v1.0-rc6