Add getScheme to DynamicInformationProvider interface

[Nick Lothian <nl...@essential.com.au>]

We're having trouble with redirects in Pluto using HTTPS.

At the moment org.apache.pluto.portalImpl.core.ResourceURLProviderImpl does 

public ResourceURLProviderImpl(DynamicInformationProviderImpl provider,
PortletWindow portletWindow)
{
   this.portletWindow = portletWindow;
   this.base = PortalURL.getBaseURLexcludeContext();
}

PortalURL.getBaseURLexcludeContext() looks like

static public String getBaseURLexcludeContext()
{
    StringBuffer result = new StringBuffer(256);

    result.append(hostNameHTTP);

    return result.toString();
}

hostNameHTTP includes the "http://" scheme.

We'd like to modify ResourceURLProviderImpl to get the scheme from the
DynamicInformationProvider. 

To do that we'd need to add a getScheme() method to the
DynamicInformationProvider interface.

I'm not too sure how that interface is used, so I wanted to check: does
anyone see any problems with that?

Nick