[1.5.0] Massive refactoring for Blockquote and Chameleon to be more extensible and accommodating of XHTMLDefinition.

- Fixed buggy chameleon-support for ins and del
. Removed context variable ParentType, replaced with IsInline, which
  is false when you're not inline and an integer of the parent that
  caused you to become inline when you are (so possibly zero)
. Removed ElementDef->type in favor of ElementDef->descendants_are_inline
  and HTMLDefinition->content_sets
. StrictBlockquote now reports what elements its supposed to allow,
  rather than what it does allow
. Removed HTMLDefinition->info_flow_elements in favor of
  HTMLDefinition->content_sets['Flow']
. Removed redundant "exclusionary" definitions from DTD roster
. StrictBlockquote now requires a construction parameter as if it
  were an Required ChildDef, this is the "real" set of allowed elements

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@710 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/HTMLModule/Text.php

@@ -37,6 +37,7 @@ class HTMLPurifier_HTMLModule_Text extends HTMLPurifier_HTMLModule
             if ($element == 'br') {
                 $this->info[$element]->content_model_type = 'empty';
             } elseif ($element == 'blockquote') {
+                $this->info[$element]->content_model = 'Heading | Block | List';
                 $this->info[$element]->content_model_type = 'strictblockquote';
             } elseif ($element == 'div') {
                 $this->info[$element]->content_model = '#PCDATA | Flow';