Add portable .NET 4.5 libary (profile 259)

Profile 259 supports .NET 4.5 + Windows 8 + Win Phone 8.1 + Win Phone + Silverlight 8

This is a very wide and popular profile, also supported by Xamarin for Android and iOS.
Add manual implementations for environment and measurement
Add console sample app for testing portable library
Fix null ref exception when LanguageCode is not set
nuspec: Use wildcards for dll files