[Fix] Multiplayer is functional again.
Problems fixed:
	Networked character was created before resources were loaded.
	Menubar was updated before it was created.
	Multiplayer vehicle selector wasn't properly invoked.
[Fix] RigParser: Section 'beams' now tolerates invalid trailing characters
[Fix] RigSpawner: node buoyancy flag "b" is now working
NOTE: Sections reordered to debug LotusEsprit_JB.truck
[Codechange] Removed rogue header-include
[Codechange] GUI classes refactored; common code moved to GuiPanelBase
[Add] RigEditor: Added node properties panel