enable use of multiple terms in first_found

This patch allows for (fixing if you will) to specify multiple terms for when_first_found:

Example:
```
- name: some configuration template
  template: src={{ item }} dest=/etc/file.cfg mode=0444 owner=root group=root
  with_first_found:
   - files:
      - ${inventory_hostname}/etc/file.cfg
     paths:
      - ../../../templates.overwrites
      - ../../../templates
   - files:
      - etc/file.cfg
     paths:
      - templates 
```

The importance for this is two fold:
1) This syntax was already valid but only remembered the last set.
2) This allows for cleaner usage of first_found. Now one has the ability to explicitly set groups of files and paths.