==What MultiDocumentSupport is==
 * support for working on several documents in same time
 * easy importing of nodes from one document to another
 * pointing document thought
   * phpQuery object
   * [http://www.php.net/manual/en/class.domnode.php DOMNode] object
   * [http://www.php.net/manual/en/class.domdocument.php DOMDocument] object
   * internal document ID
 * last created (or selected) document is assumed to be default in pq();
==What MultiDocumentSupport is NOT==
 * it's *not possible* to fetch nodes from several document in one query
 * it's *not possible* to operate on nodes from several document in one phpQuery object

==Example==
{{{
// first three documents are wrapped inside phpQuery
$doc1 = phpQuery::newDocumentFile('my-file.html');
$doc2 = phpQuery::newDocumentFile('my-file.html');
$doc3 = phpQuery::newDocumentFile('my-other-file.html');
// $doc4 is plain DOMDocument
$doc4 = new DOMDocument;
$doc4->loadHTMLFile('my-file.html');
// find first UL list in $doc1
$doc1->find('ul:first')
  // append all LIs from $doc2 (node import)
  ->append( $doc2->find('li') )
  // append UL (with new LIs) into $doc3 BODY (node import)
  ->appendTo( $doc3->find('body') );
// this will find all LIs from $doc3
// thats because it was created as last one
pq('li');
// this will find all LIs inside first UL in $doc2 (context query)
pq('li', $doc2->find('ul:first')->get());
// this will find all LIs in whole $doc2 (not a context query)
pq('li', $doc2->find('ul:first')->getDocumentID());
// this will transparently load $doc4 into phpQuery::$documents
// and then all LIs will be found
// TODO this example must be verified
pq('li', $doc4); 
}}}
==Static Methods==
 * phpQuery::*newDocument*($html) Creates new document from markup
 * phpQuery::*newDocumentFile*($file) Creates new document from file
 * phpQuery::*getDocument*($id = null) Returns phpQueryObject containing document with id $id or  default document (last created/selected)
 * phpQuery::*selectDocument*($id) Sets default document to $id
 * phpQuery::*unloadDocuments*($id = null) Unloades all or specified document from memory
 * phpQuery::*getDocumentID*($source) Returns $source's document ID
 * phpQuery::*getDOMDocument*($source) Get DOMDocument object related to $source
==Object Methods==
 * $pq->*getDocument*() Returns object with stack set to document root
 * $pq->*getDocumentID*() Get object's Document ID
 * $pq->*getDocumentIDRef*(&$documentID) Saves object's DocumentID to $var by reference
 * $pq->*unloadDocument*() Unloads whole document from memory