init of trello-237: improve journal list scrolling

Init of trello-237 feature request to improve scrolling of the
integrated-journals list, in particular to fix the table headings
while the table body containing journals is being scrolled.

This commit includes:

- adding jquery.dataTables.css, jquery.dataTables.js files
- update to page-structure.xsl and sitemap.xmap for js/css file includes
- initialization of JS table-scroll code in dryad-pages.js
- addition of thead/tbody elements in integratedJournals.xhtml for
  use by jquery.dataTables.js
css and table layout adjustments

The DataTables auto-format behavior and its stylesheet
were causing misalignment between the table's head and
body.

Updates in this commit are:

- adding "autoWidth=false" config flag during initialization
in Mirage/lib/js/dryad-pages.js
- css and table layout updates in Mirage/pages/
integratedJourals.xhtml
Merge pull request #630 from rnathanday/trello-237

Trello 237: improve scrolling in journal list