RealTimePlot: roll was actually psi. All angles now. (Backport from ce9927b659.)
LoggingDownloader: Added null pointer protection. (Partial backport of 4b75fa67.)
Updated changelog.
Merge branch 'release/neptus-3.0.x' into release/neptus-3.1.x
vehicles-defs: Fixing some IMC IDs.

Conflicts:
	vehicles-defs/82-form-leader-01.nvcl
Vehicles-defs/lauv-noptilus-1: Removed unconstrained and vehicleformation maneuvers, changed all maneuvers speed type from RPM to m/s and updated host-address.
Vehicles-defs/lauv-noptilus-2: Removed unconstrained and vehicleformation maneuvers, changed all maneuvers speed type from RPM to m/s and updated host-address.
Vehicles-defs/lauv-noptilus-3: Removed unconstrained and vehicleformation maneuvers, changed all maneuvers speed type from RPM to m/s and updated host-address.
Vehicles-defs/lauv-seacon-1: Changed all maneuvers speed type from RPM to m/s and updated host-address.
Vehicles-defs/lauv-seacon-2: Removed unconstrained manuever, changed all maneuvers speed type from RPM to m/s and updated host-address.
Vehicles-defs/lauv-seacon-3: Removed unconstrained manuever, changed all maneuvers speed type from RPM to m/s and updated host-address.
Vehicles-defs/lauv-xtreme-2: Removed unconstrained and vehicleformation maneuvers, changed all maneuvers speed type from RPM to m/s and updated host-address.
Vehicles-defs/lauv-lsts-1: Changed all maneuvers speed type from RPM to m/s and updated host-address.
Vehicles-defs/adamastor: Updated host-address and edited schema file path.
Vechiles-defs/lauv-seacon-1: added missing namespace URI and schema path.
vehicles-defs: Added new system x8-04 and its parameters.
Added LAUV-Lupis-1.
Updated changelog.