Now logging warning silently instead of crashing when xls file not found
info messages are now also logged to log
Moved html rendering of projectlink out of xlsreader so it can be a general class used to work with challenge links from xls and projects hosted on comic
Fixed small glitch with long urls messing up the table layout
projects hosted on comic now receive the correct tags for filtering
Projectlinks now sorted by date
Fixed some bugs in date sorting, added subdivision by year
Yearheadings are now hidden when not needed, improved filtering
small changes to year dividers
fixes #220, favicon is now included
refs #219
Merge branch 'Improve_projectlinks_page' into dev
added test to expose #219
silenced exceptions in contextprocessor as even Http404 is rendered as 500
server error because the exception is not thrown inside a view refs#219
Non existant site now throws 404 refs #219
test which checks non-existant site 404  refs #219