Unity 3D editor extension for checking and setting KeyName values in PlayerPrefs, and confirming the existence of a KeyName, as well as resetting all PlayrPrefs.  Currently, you an only set the value of KeyValues that already exist. In order to use this extension, place it inside a folder entitled Editor, inside any Unity project. This editor extension has been tested with Unity 3D v4.3. I do not guarantee that it will work in earlier or later versions of Unity 3D.