Move SourceLocation to CppSharp.AST.

src/AST/SourceLocation.cs

@@ -1,4 +1,4 @@
-namespace CppSharp
+namespace CppSharp.AST
 {
     /// <summary>
     /// Encodes a location in the source.

src/Parser/ASTConverter.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using SourceLocation = CppSharp.AST.SourceLocation;
 using CppSharp.Parser.AST;
 
 namespace CppSharp