Extensions are public and intellisense picks them up

[michaelpaulus]

These are public vs internal which can create issues with projects using your nuget package end up getting intellisense to use your helper methods. I want to use your package, but don't want your helper extensions that don't provide value for what we are using your package for.

SharpSimpleNLG/helperextensions/HelperExtensions.cs

SharpSimpleNLG/helperextensions/EqualsExtensions.cs

[nickhodge]

PR welcome