SimpleJson reflection rewrite with support for Win8RTM and portable library

[prabirshrestha]

Includes complete rewrite of reflection utils based on https://github.com/facebook-csharp-sdk/reflection-utils/pull/5

• supports Windows 8 RTM Store Apps
• supports Portable Class Library
• support .net 2.0/.net 3.0/.net 3.5/.net 4.0/.net 4.5
• supports sl4/sl5 (dropped support or sl3)
• supports WP7 and WP7.5 (Mango)
• removed Reflection.Emit, rather uses Compiled Linq Lambda Expressions. (you get performance benefit even in medium trust now.)
• reflection cache is per instance of PocoJsonSerializerStrategy or DataContractJsonSerializerStrategy
• getter/setters uses different cache
• new instance of arrays are now created using compiled lambdas instead of Activator.CreateInstance.
• you can force .net 4.5+ projects to use GetTypeInfo instead of GetType if you #define SIMPLE_JSON_TYPEINFO
• force ISO-2 C# language spec

Note: By default it uses linq expressions, if you are running in wp7.0 or .net<3.0 you need to #define SIMPLE_JSON_NO_LINQ_EXPRESSION