Implemented Wom3 version of stacked visitor

* sweble-wikitext d7da7ee...2fbdd66 (1):

    commit 2fbdd6669e6bc9ee60c3e55dfab6931b6a4a8c6e

        WtEngineImpl now allows to parse from wiki markup (not  only from pre processed AST)

* sweble-wom3 095348f...41bb875 (2):

    commit 41bb8759c641d8655668b1be2802e5d6d4316fd8

        Implemented Wom3 version of stacked visitor

    commit 7dd48423e369ba533c8805cd69cd2489283006ec

        Improved Wom3Document and Wom3DomImplementation interfaces by returning Wom3 node types instead of w3c parent types

* utils 389836f...1f23282 (2):

    commit 1f2328246cb726cf5f4966acf71ef2d530a8f668

        Added new visitor type: StackedVisitor

    commit 6cb357d8035317d74bc9a41a5313b1ee503fec22

        Removed unecessary try/catch that would be handled by the caller anyway