Added Restsharp.UWP project

Adjust RestSharp code with #defines as some .Net namespaces/classes/methods aren't available when targeting UWP.

Author: DSchmidlin

RestSharp.IntegrationTests/packages.config

@@ -1,5 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
-
 <packages>
-    <package id="NUnit" version="2.6.4" targetFramework="net40" />
+  <package id="NUnit" version="2.6.4" targetFramework="net4" />
 </packages>

RestSharp.Tests/packages.config

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-
 <packages>
-    <package id="NUnit" version="2.6.4" targetFramework="net35" />
-    <package id="SimpleJson" version="0.38.0" targetFramework="net35" />
+  <package id="NUnit" version="2.6.4" targetFramework="net35" />
+  <package id="SimpleJson" version="0.38.0" targetFramework="net35" />
 </packages>

RestSharp.UWP/Properties/AssemblyInfo.cs

@@ -0,0 +1,21 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following 
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("RestSharp.UWP")]
+
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version 
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers 
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: ComVisible(false)]

RestSharp.UWP/Properties/RestSharp.UWP.rd.xml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    This file contains Runtime Directives, specifications about types your application accesses
+    through reflection and other dynamic code patterns. Runtime Directives are used to control the
+    .NET Native optimizer and ensure that it does not remove code accessed by your library. If your
+    library does not do any reflection, then you generally do not need to edit this file. However,
+    if your library reflects over types, especially types passed to it or derived from its types,
+    then you should write Runtime Directives.
+
+    The most common use of reflection in libraries is to discover information about types passed
+    to the library. Runtime Directives have three ways to express requirements on types passed to
+    your library.
+
+    1.  Parameter, GenericParameter, TypeParameter, TypeEnumerableParameter
+        Use these directives to reflect over types passed as a parameter.
+
+    2.  SubTypes
+        Use a SubTypes directive to reflect over types derived from another type.
+
+    3.  AttributeImplies
+        Use an AttributeImplies directive to indicate that your library needs to reflect over
+        types or methods decorated with an attribute.
+
+    For more information on writing Runtime Directives for libraries, please visit
+    http://go.microsoft.com/fwlink/?LinkID=391919
+-->
+<Directives xmlns="http://schemas.microsoft.com/netfx/2013/01/metadata">
+  <Library Name="RestSharp.UWP">
+
+  	<!-- add directives for your library here -->
+
+  </Library>
+</Directives>