docfix: some characters must be escaped in HTML

docs/running_eHive_pipelines.html

@@ -285,7 +285,7 @@ coding_exon_stats_summary  (39)     <span style="color:black; background-color:g
          ======= TOTAL ======= : 100 active Roles
 
 Not submitting any workers this iteration
-                          hive 2.651% complete (< 432.133 CPU_hrs) (162726 todo + 4432 done + 0 failed = 167158 total)
+                          hive 2.651% complete (&lt; 432.133 CPU_hrs) (162726 todo + 4432 done + 0 failed = 167158 total)
 sleep 1.00 minutes. Next loop at Mon Sep  8 15:27:48 2014
 </pre>
 <p>NB: colours are normally not used in beekeeper's output. They have been inserted here to refer to the above-mentioned legend</p>