- re-arrange cluster initialization to a set of variables in a dictionary

which control three things:
    1. should we initialize?
    2. if so, how?
    3. what environment variables and user to use
  The approach taken is very similar to what the Apache formula uses, namely:
  a default dictionary which is over-ridden by:
     os-specific defaults,
     then os codename defaults,
     then os finger defaults,
     and finally user-specified pillar values
- this also adds support for grains['osfinger']

pillar.example

@@ -1,17 +1,19 @@
 postgres:
   pg_hba.conf: salt://postgres/pg_hba.conf
-  commands:
-    initdb: service postgresql initdb
+  prepare_cluster:
+    user: root
+    command: service postgresql initdb
+    test: test -f /path/to/some/file
+    env:
+      LC_ALL: C.UTF-8
 
   use_upstream_repo: False
 
-  lookup:
-    pkg: 'postgresql-9.3'
-    pkg_client: 'postgresql-client-9.3'
-    pkgs_extra:
-      - postgresql-contrib
-      - postgresql-plpython
-    pg_hba: '/etc/postgresql/9.3/main/pg_hba.conf'
+  pkg: 'postgresql-9.3'
+  pkg_client: 'postgresql-client-9.3'
+  pkgs_extra:
+    - postgresql-contrib
+    - postgresql-plpython
 
   users:
     localUser: