#686060 by Crell, David_Rothstein, dww, yoroy, carlos8f, et al: Fixed Explain that the Update manager only works if you have FTP or SSH access to your server

- Patch #700558 by dww: add test to ensure filename extensions are properly merged in the Update manager UI.

- Patch #502190 by jhodgdon, stella, sun: hook implementation headers out of compliance with standards.