many changes
Merge branch 'master' of https://github.com/destenson/AlgebraCpp

Conflicts:
	Algebra/Math/Algebra.Internals/Algebra.cs
	Algebra/Math/Algebra.Internals/Expression.Internal.cs
	Algebra/Math/Algebra.Internals/Expression.cs
	Algebra/Math/Algebra.Internals/ExpressionCollection.cs
	Algebra/Math/Algebra.Internals/Polynomial.cs