NSEdoc cleanup

Mostly splitting function summaries (the first paragraph of NSEdoc) from
the body of the description to make the summary indexes shorter and
easier to scan.

Also fixed some unbalanced code tags like <code>foo</table>

nselib/iscsi.lua

@@ -423,6 +423,7 @@ Packet = {
 }
 
 --- The communication class handles socket reads and writes
+--
 -- In addition it keeps track of both immediate packets and the amount of read
 -- packets and updates cmdsn and expstatsn accordingly.
 Comm = {