Remove early return in nsExternalProtocolHandler::NewChannel when handler doesn't exist.
Fix devtools expectation that newChannel throws for unsupported external handlers
Vim control lines were re-introduced or not entirely cleaned up.
This nukes them again.
Removing from accessible, [root], tools, uriloader, widget, xpcom and
xpfe.
Resolves#1656
About time we stopped looking at Netscape 4.x entries in the registry ;)
Also, assume the application association API is present in Windows
and use that instead of reading from the registry directly.
