Humanize extension reinstantiates Regex objects unnecessarily

[dlras2]

StringHumanizeExtensions.Humanize and StringHumanizeExtensions.FromPascalCase are reinstantiating their respective Regex objects on every call. These constructor calls can make up over half the execution time of Humanize(), as seen in the screenshot below. This can be fixed by using the cached static Regex.IsMatch method or instantiating the necessary Regex only in the static constructor of StringHumanizeExtensions.