add script that generates .png files with activity charts
missing file lines.plot
Merge branch 'master' into graphs
create images in cgi/images/
first shot at including activity images in index page
fix markup
more markup fixes
more markup fixes, .gitignore
do not count joins/leaves etc. for activity graphs
[channel-index] do not link to join/quit-only days
[cron-graphs] make output dir parameterizable

default to cgi/images/index/, to make room for other images