Mono.Data.Sqlite for Windows Store Apps

Adding support for ADO.NET and SQLite for ADO.NET to Windows Store Apps:
 - Silverlight for Windows Phone 8.0/8.1
 - Windows Runtime for Store 8.0/8.1 and Windows Phone 8.1

Changes:
 - Added new pre-processor directives:
 -- WINDOWS_STORE_APP for any Windows device build
 -- WINDOWS_PHONE for Silverlight for Windows Phone
 -- NETFX_CORE for Windows Runtime
 - Removed WinForms designer attributes
 - Removed Binary serialization (SerializableAttribute and ISerializable)
 - Added C++ project to build the managed sqlite3.dll bindings (DllImport is unavailable in Silverlight for Windows Phone)
 - Removed Microsoft.SqlServer.Server and System.Data.SqlClient namespaces due to Mono.Data.Tds being unavailable at this time
 - Improvised support for IConvertible by checking the actual type
 - Using the String.Compare overload that accepts StringComparision
 - Added XML serialization attributes to SqlTypes
 - Removed LCID support from SqlString
 - Removed the old NUnit method of using the Assertion base class for tests
 - Removed the NUnit [ExpectedException] attribute as this hides any erroneous exceptions of the same type
 - Using StringComparision.OrdinalXXX instead of StringComparision.InvariantCultureXXX
 - Using using statements when creating XmlReaders/Writers instead of try/catch/finally

To Do:
 - Add back MS SQL Server
 - Complete SqlString