Recommendation Tracker Code

Merged changes from the trunk into the xhtml branch

Set tooltip of mixed content text areas to preview the marked up contents.

Added XHTML support for elements which have such support in XCCDF.
For feature requests:
2844623 - support XHTML on export,
2844622 - support XHTML on import
2019813 - support XHTML in descriptions

Modified schema to allow mixed content in most description fields.
Changed code enough for RT to work as before.

Creating branch for adding support for XHTML