Lots of work on rewriting functions to allow more functionality

UpsilonTests/TableTests.cs

@@ -1,3 +1,4 @@
+using System;
 using Upsilon.Evaluator;
 using Xunit;
 
@@ -104,9 +105,9 @@ return table[""test""]()
             const string input = @"
 table = {
     function func()
-        return function func()
+        return function()
             return {
-                function func()
+                function()
                     return 100
                 end
             }