(DNN-4704) Add NavigateURL and FriendlyUrl to TestableGlobals

Copy comments from IGlobals to Globals for FriendlyUrl and NavigateURL
(DNN-4704) Add GetPortalDomainName to TestableGlobals
(DNN-4704) Add AddHTTP method to TestableGlobals
(DNN-4704) Add IsHostTab to TestableGlobals
(DNN-4704) Add AccessDeniedURL to TestableGlobals
(DNN-4704) Add LoginUrl to TestableGlobals
(DNN-4704) Add FormatHelpUrl to TestableGlobals
(DNN-4704) Use TestableGlobals where NavigateURL is used
Merge pull request #54 from bdukes/DNN-4704

(DNN-4704) Add more APIs to TestableGlobals