php4-html-dom: Fast HTML Parser for PHP Code

- Added htmlNode->addSibling(). Adds a sibling right after the node the methodis called on.
- Added htmlNode->getText(). Returns the content of the text nodes (ttText).
- Added Parser Option poNone: Default to no options
- Added htmlNode->getInnerHtml(). Returns the HTML of all the children.
- Corrected indexing in node->insertChildNode()