Merge pull request #10 from guimaluf/rename_ptr_value_to_ip

Rename ptr value to ip, dhcpboot with less params, tag to dhcpoption.
Revert "Rename value to ip on ptr class and template"

This reverts commit 558181e997bfeb39c08b306418e082064de34c91.
[README] update with new changes & show some optional options
[docs] prepare for 2.4.0 release
[template/main class] add config_hash option
[fix] removed use of private concat class
[dnsmasq.conf] save commented original before replacing
[service] configurable service state
[service] use generic service name
add: dnsserver_simple define
upd: make dnsmasq config dir optional
upd: made mx parameters optional as per man page
Merge branch 'flypenguin-mods'

* flypenguin-mods:
  upd: made mx parameters optional as per man page
  upd: make dnsmasq config dir optional
  add: dnsserver_simple define
  [service] use generic service name
  [service] configurable service state
  [dnsmasq.conf] save commented original before replacing
  [fix] removed use of private concat class
  [template/main class] add config_hash option
Revert "add: dnsserver_simple define"

This reverts commit 0e1fc0888a2925e84be54640865bd962315a0e56.
[dnsserver] support empty domain variable
[dnsserver] syntax fixes
[dnsserver] even better syntax
[dnsserver] more fixes. Forgot how to code. Derp
[dnsserver] undef  by default
[docs] update for master