This class is a simple wrapper around 
Foswiki::Prefs::Stack. Since Webs has an
hierarchical structure it's needed only one stack to deal with preferences from
Web and Web/Subweb and Web/Subweb/Subsubweb. This class has a reference to a
stack and the level where the web is.
This class is used by 
Foswiki::Prefs to pass web preferences to 
Foswiki::Meta
and should not be used for anything else.
  ClassMethod new( $session ) 
Creates a new 
WebPrefs object. 
  ObjectMethod finish() 
Break circular references.
  ObjectMethod isInTopOfStack() → $boolean 
Returns true if this web is the hihger of the underlying stack object.
  ObjectMethod stack() → $stack 
Read-only accessor to the underlying stack object.
  ObjectMethod cloneStack($level) → $stack 
This method clone the underlying stack object, to the given $level. See
Foswiki::Prefs::Stack::clone documentation.
This method exists because 
WebPrefs objects are used by 
Foswiki::Prefs instead
of bar 
Foswiki::Prefs::Stack and this operation is needed.
  ObjectMethod get($pref) → $value 
Returns the $value of the given $pref.