Make the formula fully pillar driven/customizable

- split package and param into separate state files
- use defaults.yml to specify all configurable options of the formula
- setup map.jinja to read in defaults.yml, filter by os_family for
  Arch, and merge in sysctl:lookup pillar
- Updated README

sysctl/defaults.yml

@@ -0,0 +1,14 @@
+# -*- coding: utf-8 -*-
+# vim: ft=yaml
+sysctl:
+  pkg: procps-ng
+  config:
+    location: '/etc/sysctl.d'
+  params:
+    - 
+      name: fs.file-max
+      value: 100000
+      config: fs.conf
+    - 
+      name: vm.swappiness
+      value: 20