Before this change if a variable was of type int or bool and the variable was referenced
by another variable, the type would change to string.

eg. defaults/main.yml
```
PORT: 4567
OTHER_CONFIG:
  secret1: "so_secret"
  secret2: "even_more_secret"

CONFIG:
  hostname: "some_hostname"
  port: "{{ PORT }}"
  secrets: "{{ OTHER_CONFIG }}"
```

If you output `CONFIG` to json or yaml, the port would get represented in the output as a
string instead of as a number, but secrets would get represented as a dictionary.  This is
a mis-match in behaviour where some "types" are retained and others are not.  This change
should fix the issue.

Update template test to also test var retainment.

Make the template changes in v2.
Update to only short-circuit for booleans and numbers.

Added an entry to the changelog.