Create MS.SqlTools.Credentials project (#249)

* Initial credential service files

* Clean-up hostloader

* Update build scripts to build credentials archive

* Move hosting files to new assembly

* Add credentials files to MS.SqlTools.Credentials

* Remove duplicate files

* Update namespace in program.cs

* Fix test build breaks

* Update extensions visibility.

* Remove unused resource strings

* Add xproj files to SLN for appveyor builds

* Fix appveyor build break in test project

* Fix extensibility tests

* Fix various typos in latest iteration

* Add settings for Integration build

* Fix codecoverage.bat to use full pdb for new projects

* Fix bug when packing in folder with native images

* Fix typos in xproj

* Reset XLF to fix build.cmd

src/Microsoft.SqlTools.Hosting/Hosting/Contracts/ServerCapabilities.cs

@@ -0,0 +1,67 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+namespace Microsoft.SqlTools.ServiceLayer.Hosting.Contracts
+{
+    public class ServerCapabilities
+    {
+        public TextDocumentSyncKind? TextDocumentSync { get; set; }
+
+        public bool? HoverProvider { get; set; }
+
+        public CompletionOptions CompletionProvider { get; set; }
+
+        public SignatureHelpOptions SignatureHelpProvider { get; set; }
+
+        public bool? DefinitionProvider { get; set; }
+
+        public bool? ReferencesProvider { get; set; }
+
+        public bool? DocumentHighlightProvider { get; set; }
+
+        public bool? DocumentFormattingProvider { get; set; }
+
+        public bool? DocumentRangeFormattingProvider { get; set; }
+
+        public bool? DocumentSymbolProvider { get; set; }
+
+        public bool? WorkspaceSymbolProvider { get; set; }
+    }
+
+    /// <summary>
+    /// Defines the document synchronization strategies that a server may support.
+    /// </summary>
+    public enum TextDocumentSyncKind
+    {
+        /// <summary>
+        /// Indicates that documents should not be synced at all.
+        /// </summary>
+        None = 0,
+
+        /// <summary>
+        /// Indicates that document changes are always sent with the full content.
+        /// </summary>
+        Full,
+
+        /// <summary>
+        /// Indicates that document changes are sent as incremental changes after
+        /// the initial document content has been sent.
+        /// </summary>
+        Incremental
+    }
+
+    public class CompletionOptions
+    {
+        public bool? ResolveProvider { get; set; }
+
+        public string[] TriggerCharacters { get; set; }
+    }
+
+    public class SignatureHelpOptions
+    {
+        public string[] TriggerCharacters { get; set; }
+    }
+}
+