Do not auto promote dotted facts to structured

Facter 4 (up to 4.0.52) provides a way to create structured facts from multiple fact definitions. However, the feature is not compatible with other parts of the Puppet ecosystem and can cause facts to be named differently in Facter 4 than in Facter 2/3.

In order to avoid changing Puppet manifests, hiera lookups, PE classification rules, dotted custom and external facts should not be automatically promoted to structured facts.

Treating those facts as structured will still be possible by usging a global facter setting which by default is set to false.

Eg:

default behavior

# custom fact

Facter.add('a.b.c') do

  setcode { "d" }

end

# external fact

a.b.c=d

is represented as { "a.b.c": "d" }

setting true

# custom fact

Facter.add('a.b.c') do

  setcode { "d" }

end

# external fact

a.b.c=d

is represented as 

{

  "a": {

    "b": {

      "c": "d"

    }

  }