Item12952: Add trace to AutoConfigure

We can delete this later, but some trace info gives us a chance to
figure out how autoconfigure came to it's conclusions.

Add a default for pub if short urls resulted in no bin directory.

Clean up directory paths,  try to eliminate any relative paths.

Finally.  Foswiki.spec was overwiting the bootstrapping of
{ScriptUrlPaths}{view}

Tested with 3 configurations:
 - ApacheConfigGenerator with short URLs,  and /foswik/ path
    website.com/foswiki/Main/WebHome
 - ACG with no shortening
    website.com/foswiki/bin/view/Main/WebHome
 - NewApacheConfigGenerator with short urls
    website.com/Main/WebHome

We really need this tested with other servers, esp. lighttpd, nginx,
IIS,