upgrade to DataTables 1.10.4

need the bugfix DataTables/DataTables#391
Bootstrap 3 for DataTables
the css of the processing indicator seems to be okay with Bootstrap 3 now
Fix DOM structure for selectize inputs
Wrap select inputs in div
Update tests for new select input structure
update the version info of DataTables
Merge pull request #646 from yihui/feature/DT-1.10.3

upgrade to DataTables 1.10.4 and use Bootstrap 3
Fix appearance of DataTables examples
Limit width of inputs
Better help for reactiveValues. Fixes #620
Dynamically get font-awesome dependency from showcase body
Merge pull request #655 from wch/showcase-dep

Dynamically get font-awesome dependency from showcase body
Fix file input appearance for Bootstrap 3
Switch from RJSONIO to jsonlite