Add more revit tests.
More work on Issue #316.
Refactored our previous Measure types into a number of static classes with methods for conversion.
Removed all references to measure types.
Fixed all tests.
Merge branch 'master' of github.com:ikeough/Dynamo

Conflicts:
	src/DynamoCore/Core/Units.cs
	src/DynamoElementsTests/UnitsOfMeasureTests.cs