Change the stylesheet implementation. It is now based on selectors.

Mode:

- change in the way style for a node is computed. Introduction of a fullpath property in nodes that is needed by the style assignment algorithm.
- removal of a graph traversal operation that was needed to mark unmarked nodes. It is now included in the first vtraversal that takes care of marking markable nodes.
- removal of hardcoded default css classNames.


Stylesheet

- change in the way styles are associated to a node. It is now based on fullpaths. You can now define styles that apply to an certain path. For example, if you want id's in attributes to have a certain style, you can add a rule for 'attribute.id'. You can also add more specific rules by using a path. The most precise one will be chosen for a certain node.

HTML Grammar:

- removed the parent dependent element type (used for distinguishing id's present in the opening tag or in an attribute).