Cleaned up some unused usings.

src/Generator/Driver.cs

@@ -1,5 +1,7 @@
 using System;
 using System.CodeDom.Compiler;
+using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Reflection;
 using System.Text;
@@ -9,8 +11,6 @@ using CppSharp.Generators.CLI;
 using CppSharp.Generators.CSharp;
 using CppSharp.Passes;
 using CppSharp.Types;
-using System.Collections.Generic;
-using System.IO;
 using Microsoft.CSharp;
 
 #if !OLD_PARSER

src/Generator/Passes/FunctionToStaticMethodPass.cs

@@ -1,5 +1,4 @@
-using System;
-using CppSharp.AST;
+using CppSharp.AST;
 
 namespace CppSharp.Passes
 {

tests/CSharpTemp/CSharpTemp.Tests.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Linq;
 using System.Reflection;
 using CSharpTemp;
 using NUnit.Framework;