added bootstrap 3.0.0 to the project tree
using bootstrap 3

moved the exercise list into a second column
hide the exercise list on narrow widths
error section changed to warning, because of change in bootstrap
scoreboard for the whole course

the javascript can be reused to make scoreboards for every chapter
multi column scoreboard
Rough first version link to index page
Merge branch 'master' into gh-pages
Scoreboard