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
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