Implement T4 template support to generat unit classes based on Unit enum values tagged with attributes.

* Using wildcards in .csproj files to automatically load files.
* Fixed all tests, mostly due to improved precision of constants and not using Delta.
* Added ToString() to vectors.
* In test code, disabled build warning CS1718: Comparison made to same variable; did you mean to compare something else?

BREAKING BACKWARDS COMPATIBILITY
==================================
* Fixed case and plural naming of units: Kilopascal, Megapascal, RevolutionPerSecond

Author: angularsen

Src/UnitsNet/Area.cs

@@ -0,0 +1,139 @@
+// Copyright © 2007 by Initial Force AS.  All rights reserved.
+// https://github.com/InitialForce/UnitsNet
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+using System;
+
+namespace UnitsNet
+{
+    [AttributeUsage(AttributeTargets.Field)]
+    public class LengthAttribute : UnitAttribute
+    {
+        public LengthAttribute(double ratio, string pluralName = null) : base(pluralName, ratio)
+        {
+        }
+    }
+
+    [AttributeUsage(AttributeTargets.Field)]
+    public class MassAttribute : UnitAttribute
+    {
+        public MassAttribute(double ratio, string pluralName = null) : base(pluralName, ratio)
+        {
+        }
+    }
+
+    [AttributeUsage(AttributeTargets.Field)]
+    public class AngleAttribute : UnitAttribute
+    {
+        public AngleAttribute(double ratio, string pluralName = null) : base(pluralName, ratio)
+        {
+        }
+    }
+
+    [AttributeUsage(AttributeTargets.Field)]
+    public class AreaAttribute : UnitAttribute
+    {
+        public AreaAttribute(double ratio, string pluralName = null) : base(pluralName, ratio)
+        {
+        }
+    }
+
+    [AttributeUsage(AttributeTargets.Field)]
+    public class ElectricPotentialAttribute : UnitAttribute
+    {
+        public ElectricPotentialAttribute(double ratio, string pluralName = null) : base(pluralName, ratio)
+        {
+        }
+    }
+
+    [AttributeUsage(AttributeTargets.Field)]
+    public class FlowAttribute : UnitAttribute
+    {
+        public FlowAttribute(double ratio, string pluralName = null) : base(pluralName, ratio)
+        {
+        }
+    }
+
+    [AttributeUsage(AttributeTargets.Field)]
+    public class ForceAttribute : UnitAttribute
+    {
+        public ForceAttribute(double ratio, string pluralName = null) : base(pluralName, ratio)
+        {
+        }
+    }
+
+    [AttributeUsage(AttributeTargets.Field)]
+    public class PressureAttribute : UnitAttribute
+    {
+        public PressureAttribute(double ratio, string pluralName = null) : base(pluralName, ratio)
+        {
+        }
+    }
+
+    [AttributeUsage(AttributeTargets.Field)]
+    public class RotationalSpeedAttribute : UnitAttribute
+    {
+        public RotationalSpeedAttribute(double ratio, string pluralName = null) : base(pluralName, ratio)
+        {
+        }
+    }
+
+    [AttributeUsage(AttributeTargets.Field)]
+    public class TorqueAttribute : UnitAttribute
+    {
+        public TorqueAttribute(double ratio, string pluralName = null) : base(pluralName, ratio)
+        {
+        }
+    }
+
+    [AttributeUsage(AttributeTargets.Field)]
+    public class VolumeAttribute : UnitAttribute
+    {
+        public VolumeAttribute(double ratio, string pluralName = null) : base(pluralName, ratio)
+        {
+        }
+    } 
+
+    [AttributeUsage(AttributeTargets.Field)]
+    public class UnitAttribute : Attribute
+    {
+        /// <summary>
+        /// Ratio of unit to base unit. For example, <see cref="Unit.Kilometer"/> is 1000:1 of the base unit <see cref="Unit.Meter"/>.
+        /// </summary>
+        public readonly double Ratio;
+
+        /// <summary>
+        /// Name of unit in plural form. Will be used as property name such as Force.FromNewtonmeters().
+        /// </summary>
+        public readonly string PluralName;
+
+        ///// <summary>
+        ///// Name of unit in singular form. Will be used as ???.
+        ///// </summary>
+        //public string SingularName { get; set; }
+
+        public UnitAttribute(string pluralName, double ratio)
+        {
+            Ratio = ratio;
+            PluralName = pluralName;
+            //SingularName = null;
+        }
+    }
+}