Update ruby-nokogiri package to 1.4.5.

=== 1.4.5 / 2011-06-15

* New Features

  * Nokogiri::HTML::Document#title accessor gets and sets the document title.
  * extracted sets of Node::SaveOptions into
    Node::SaveOptions::DEFAULT_{X,H,XH}TML (refactor)
  * Raise an exception if a string is passed to Nokogiri::XML::Schema#validate.
    #406

* Bugfixes

  * Node#serialize-and-friends now accepts a SaveOption object as the, erm,
    save object.
  * Nokogiri::CSS::Parser has-a Nokogiri::CSS::Tokenizer
  * [JRUBY+FFI only] Weak references are now threadsafe. #355
  * Make direct start_element() callback (currently used for
    HTML::SAX::Parser) pass attributes in assoc array, just as
    emulated start_element() callback does.  rel. #356
  * HTML::SAX::Parser should call back a block given to parse*() if any, just
    as XML::SAX::Parser does.
  * Add further encoding detection to HTML parser that libxml2 does not do.
  * Document#remove_namespaces! now handles attributes with namespaces. #396
  * XSLT::Stylesheet#transform no longer segfaults when handed a
    non-XML::Document. #452
  * XML::Reader no longer segfaults when under GC pressure. #439

(taca)