Log Message:
Update ruby-hpricot to version 0.6.  Changes from version 0.5.140 include:

+ Install as a Ruby gem.

* Hpricot for JRuby

* Inline Markaby for Hpricot documents.

* XML tags and attributes are no longer downcased like HTML is.

* new syntax for grabbing everything between two elements using a
  Range in the s earch method: (doc/("font".."font/br")) or \ 
in nodes_at
  like so: (doc/"font").nod es_at("*".."br"). Only \ 
works with either
  a pair of siblings or a set of a parent and a sibling.

* Ignore self-closing endings on tags (such as form) which are
  containers. Treat them like open parent tags.

* Escaping of attributes.

* Element#raw_attributes gives unescaped data.  Element#attributes
  gives escaped.

* Added: Elements#attr, Elements#remove_attr, Elements#remove_class.

* Added: Traverse#preceding, Traverse#following, Traverse#previous,
  Traverse#next.