add references to bcp38
resolves issue #11

change to output rules: 'minute' to 'min' and remove equal sign from
between --log-prefix and it's argument
additional fixes for issue #11
add pre and post hooks to fire script
remove confusing example rules file. keep other simpler example files
add comments to rules.conf.simple
add ignore_multicast option

when enabled, multicast packets will bypass the anti-spoof checks to
avoid erroneous logging of spoofed packets. this happens when the switch
a host is connected to is not doing igmp and therefore floods the
multicast packets to all ports.
remove rules.conf.example from Makefile
fix bug in calling unknown_keyword() from compile_intercept()
Depreciate usage of '%' as a variable sigil
fix compilation of "redirect" rules
fix grammer
fix indentation/spacing
remove some DRY code
remove useless code
refactor to remove useless extra function
refactor to remove useless extra function
refactor a loop
rename sub "compile_nat" to "compile_dnat"
update copyright year