v3.0.0

• Clean up the NuGet package.
• Improve the experience for .NET Framework 4.0 and onward (fewer unnecessary .NET Standard DLLs being pulled in on install).
• Drop support for .NET 3.5 and .NET Standard 1.1.

v2.0.1

• Add support for .NET Standard 2.0.

v2.0.0

• Add support for .NET standard.
• Add support for nullable types in the null check and comparison guards.
• Add 'IsNullOr...' comparison methods for nullable types.
• Add a 'string contains' guard.
• Clean up doco, method signatures, and test names.