Added unit tests
TryConvertReturnsFalseOnIncompatibleUnits in UnitConverterTests.cs
Added UnitValueTests.cs and TryConvertReturnsFalseOnIncompatibleUnits.
Fixed two TryConvert unit tests. Had to do major rewrite of UnitConverter to use TryConvert all the way through.
Use of TryConvert pattern for Volume dynamic conversion implemented.
Additional complex merge https://github.com/InitialForce/UnitsNet

Conflicts:
	Src/UnitsNet/UnitConverter.cs
	Tests/UnitConverterTests.cs