Merge pull request #27 from alvarezp/master

manpages: fix dashes as hyphens as detected by lintian
Fix formatting errors
Fix issues with learning next hop
Fix net-hop determination problems
Fix Linux definitions
Add contributors
Fix breakage in scan6 tool for local scans
Fix typo for BSD and Mac OS definition of tcp_hdr
Updated contributors list
Make help info reflect actual option names
Fix Mac OS breakage