Mege dev to master (#6)

* Merge master to dev (#4)

* Misc. clean-ups related to removing unneeded PowerShell Language Service code.
* Remove unneeded files and clean up remaining code.
* Enable file change tracking with Workspace and EditorSession.

* Merge ServiceHost xUnit test project into dev. (#5)

* Setup standard src, test folder structure.  Add unit test project.

* Actually stage the deletes.  Update .gitignore

src/ServiceHost/Workspace/BufferRange.cs

@@ -0,0 +1,123 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System;
+using System.Diagnostics;
+
+namespace Microsoft.SqlTools.EditorServices
+{
+    /// <summary>
+    /// Provides details about a range between two positions in
+    /// a file buffer.
+    /// </summary>
+    [DebuggerDisplay("Start = {Start.Line}:{Start.Column}, End = {End.Line}:{End.Column}")]
+    public class BufferRange
+    {
+        #region Properties
+
+        /// <summary>
+        /// Provides an instance that represents a range that has not been set.
+        /// </summary>
+        public static readonly BufferRange None = new BufferRange(0, 0, 0, 0);
+
+        /// <summary>
+        /// Gets the start position of the range in the buffer.
+        /// </summary>
+        public BufferPosition Start { get; private set; }
+
+        /// <summary>
+        /// Gets the end position of the range in the buffer.
+        /// </summary>
+        public BufferPosition End { get; private set; }
+
+        /// <summary>
+        /// Returns true if the current range is non-zero, i.e.
+        /// contains valid start and end positions.
+        /// </summary>
+        public bool HasRange
+        {
+            get
+            {
+                return this.Equals(BufferRange.None);
+            }
+        }
+
+        #endregion
+
+        #region Constructors
+
+        /// <summary>
+        /// Creates a new instance of the BufferRange class.
+        /// </summary>
+        /// <param name="start">The start position of the range.</param>
+        /// <param name="end">The end position of the range.</param>
+        public BufferRange(BufferPosition start, BufferPosition end)
+        {
+            if (start > end)
+            {
+                throw new ArgumentException(
+                    string.Format(
+                        "Start position ({0}, {1}) must come before or be equal to the end position ({2}, {3}).",
+                        start.Line, start.Column,
+                        end.Line, end.Column));
+            }
+
+            this.Start = start;
+            this.End = end;
+        }
+
+        /// <summary>
+        /// Creates a new instance of the BufferRange class.
+        /// </summary>
+        /// <param name="startLine">The 1-based starting line number of the range.</param>
+        /// <param name="startColumn">The 1-based starting column number of the range.</param>
+        /// <param name="endLine">The 1-based ending line number of the range.</param>
+        /// <param name="endColumn">The 1-based ending column number of the range.</param>
+        public BufferRange(
+            int startLine,
+            int startColumn,
+            int endLine,
+            int endColumn)
+        {
+            this.Start = new BufferPosition(startLine, startColumn);
+            this.End = new BufferPosition(endLine, endColumn);
+        }
+
+        #endregion
+
+        #region Public Methods
+
+        /// <summary>
+        /// Compares two instances of the BufferRange class.
+        /// </summary>
+        /// <param name="obj">The object to which this instance will be compared.</param>
+        /// <returns>True if the ranges are equal, false otherwise.</returns>
+        public override bool Equals(object obj)
+        {
+            if (!(obj is BufferRange))
+            {
+                return false;
+            }
+
+            BufferRange other = (BufferRange)obj;
+
+            return
+                this.Start.Equals(other.Start) &&
+                this.End.Equals(other.End);
+        }
+
+        /// <summary>
+        /// Calculates a unique hash code that represents this instance.
+        /// </summary>
+        /// <returns>A hash code representing this instance.</returns>
+        public override int GetHashCode()
+        {
+            return this.Start.GetHashCode() ^ this.End.GetHashCode();
+        }
+
+        #endregion
+    }
+}
+