complete move of truetype, afm and standard14 fonts

the 3 font types mentioned are moved to the new fonts project, any referenced types are moved to the core project. most truetype classes are made public #8.

src/UglyToad.PdfPig/XObjects/XObjectFactory.cs

@@ -4,15 +4,13 @@
     using System.Collections.Generic;
     using System.Linq;
     using Content;
-    using Exceptions;
+    using Core;
     using Filters;
-    using Geometry;
     using Graphics;
     using Graphics.Colors;
     using Graphics.Core;
     using Tokenization.Scanner;
     using Tokens;
-    using Util;
 
     internal static class XObjectFactory
     {