Fixes, cleanups, comments

Fixes, cleanups, comments

- More comments added to the code
- ICMP and ICMPv6 support added to the hash:ip,port, hash:ip,port,ip
  and hash:ip,port,net types
- hash:net and hash:ip,port,net types are reworked
- hash:net,port type added
- Wrong direction parameters fixed in hash:ip,port
- Helps and manpage are updated
- More tests added
- Ugly macros are rewritten to functions in parse.c
  (Holger Eitzenberger)
- resize related bug in hash types fixed (Holger Eitzenberger)
- autoreconf patches by Jan Engelhardt applied
- netlink patch minimalized: dumping can be initialized by a second
  parsing of the message (thanks to David and Patrick for the suggestion)
- IPv4/IPv6 address attributes are introduced in order to fix the context
  (suggested by David)