improve the legend

by using different letters for each column as suggested by TOBYINK
and also providing a title for each letter
allow tagging columns to not be sorted by table sorter
improve layout for table sorter icons
fix saving of the sort-order to not require a 'table' class and to be able to handle tables with more than 9 columns
apply sorting
tag dashboard columns that shouldn't be sorted, and sort date properly
Merge pull request #1359 from haarg/dashboard-sort

Dashboard sorting
Merge pull request #1358 from szabgab/szabgab/dashboard-legend

improve the dashboard legend
remove hideTOC cookie
convert busy indicator on contributors page with font-awesome
Add link tag for feed url to news page

fixes gh-1369.
make styling on activity graph label more specific
remove redundant style
improve directory selection in app.psgi to fix running tests outside harness
allow arbitrary number of js/css assets in wrapper
just use normal psgix.assets for less generated css
in dev mode, include css/js files directly rather than concatenated
restore proper overflowing on recent page date column
fix markup on dashboard for items not missing
don't show percent sign on dashboard if there is no ratio