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/smb.lua

@@ -460,6 +460,7 @@ function start_raw(host, port)
 end
 
 --- This function will take a string like "a.b.c.d" and return "a", "a.b", "a.b.c", and "a.b.c.d".
+--
 --  This is used for discovering NetBIOS names. If a NetBIOS name is unknown, the substrings of the
 --  DNS name can be used in this way.
 --