Put wikimodel integration prototype available in the xwiki-sandbox

WikiModel offers a model for wiki documents. It contains two different models: Wiki Event Model (WEM) - like Simple API for XML (SAX), Wiki Object Model (WOM) - like Document Object Model for XML (DOM). WikiModel also provides a JavaCC-based parser for wiki-syntax.

• WikiModel: http://nepomuk.semanticdesktop.org/xwiki/bin/view/Components/WikiModel
• See also: http://www.xwiki.org/xwiki/bin/view/Idea/WikiModelIntegration