Replaced nmap's hex dump functions with new hexdump() included in nbase. Before

Nmap used two functions: one of them, hdump(), just printed raw hex bytes 
(no ASCII equivalents) and the other one, lamont_hdump() had a bug when 
printing buffers where bufflen%16==3. A new function has been implemented 
from scratch, that basically produces the same output as Wireshark. 
Output looks like this:

0000   e8 60 65 86 d7 86 6d 30  35 97 54 87 ff 67 05 9e  .`e...m05.T..g..
0010   07 5a 98 c0 ea ad 50 d2  62 4f 7b ff e1 34 f8 fc  .Z....P.bO{..4..
0020   c4 84 0a 6a 39 ad 3c 10  63 b2 22 c4 24 40 f4 b1  ...j9.<.c.".$@..

Changes:

- The new hexdump() function has been added to nbase.
- Old hdump() and lamont_dump() have been removed from nmap's code.
- A wrapper to the new hexdump(), called nmap_hexdump(), has been added
  to nmap's utils.cc. The wrapper basically prints the buffer returned 
  by hexdump() using nmap's log_write() function.

tcpip.cc

@@ -2223,7 +2223,7 @@ if (!pd) fatal("NULL packet device passed to %s", __func__);
      fatal("FATAL: %s: bogus caplen from libpcap (%d) on interface type %d", __func__, head.caplen, datalink);
    } 
    error("FATAL:  Unknown datalink type (%d). Caplen: %d; Packet:", datalink, head.caplen);
-   lamont_hdump(p, head.caplen);
+   nmap_hexdump((unsigned char*)p, head.caplen);
    exit(1);
  }