- 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']

postgres/osfingermap.yaml

@@ -0,0 +1 @@
+{}