+ Peter Speck <speck@vitality.dk> eps/svg/pdf file format code in rrdtool-1.x
+ David Grimes <dgrimes@navisite.com> SQRT/SORT/REV/SHIFT/TREND
+ Henrik Storner <henrik@hswn.dk> make rrd_graph() provide the min/max values of data in graph
+ Radoslaw Karas <rkaras@tyndall.ie>