Update kOS.csproj

Added file VesselSensors.cs
Create VesselSensors.cs

VesselSensors projects sensors to the scripting language
Added SENSOR to the scripting language.

Sensors attached to the ship can now be accessed by SENSOR:[ACC|GRAV|TEMP|PRES].
Changed sensor sources.

Sensor source values has been changed so that the values is now pulled from the same places done when KSP decides what to show in the display of the stock parts.
Corrected accelerometer data.

Accelerometer did not report the gravity acceleration in addition to the acceleration relative to the gravity source. Now it does.
Corrected accelerometer data. Again...

Fixed sign-bug.
Merge branch 'master' of https://github.com/palaslet/KOS