Use static config access method instead extension method.

Renames extension class to `FeatureSwitch`. Deprecated the old way.
Bump to v1.0.1
Adjust readme code example
Rename static config reader class to `FeatureSwitchSetting`
Merge branch 'static-access' of https://github.com/ilkerde/c24.FeatureSwitcher into ilkerde-static-access

Conflicts:
	c24.FeatureSwitcher.nuspec
Merge branch 'ilkerde-static-access'