Rename project to UnitsNet.Portable40
Add .NET 4.5 portable project (profile 259)

Fix incompatible code
Remove unused EnumUtils.cs with compile error in new profile
Add portable45 project to build script
Use nuget platform subfolders per project build output

Use wildcards in .nuspec to add all files with respective subfolders
Add .NET 4.5.1 target
Rename to fix capitalization of project
Bump to 3.1.0
Merge branch 'release/3.1.0'
Merge tag '3.1.0' into develop

Add nuget targets for .NET 4.5 and portable