Add CSS style class to XHTML tags

Add support for CSS style formatting with a class property on tags.

Previously filed http://jira.codehaus.org/browse/MNG-545.

Patches for core and sink-api for doxia-1.0-alpha-8 attached.

It provides the following fixes:

1. class property on list and numbered list tag
2. class property on paragraph tag
3. class property on link tag
4. target property on link tag
5. class property on table cells
6. class property on table header cells
7. class property on anchors

Is this an acceptable request or have people achieved CSS style differently when generating XHTML using Doxia?

Thanks