Make use of yes/no booleans in playbooks

At the moment Ansible prefers yes/no for module booleans, however booleans in playbooks are still using True/False, rather than yes/no. This changes modifies boolean uses in playbooks (and man pages) to favor yes/no rather than True/False.

This change includes:

- Adaptation of documentation and examples to favor yes/no
- Modification to manpage output to favor yes/no (the docsite output already favors yes/no)

examples/playbooks/postgresql.yml

@@ -7,8 +7,8 @@
 #
 ---
 - hosts: webservers
-  sudo: True
-  gather_facts: False
+  sudo: yes
+  gather_facts: no
 
   tasks:
   - name: ensure apt cache is up to date
@@ -21,9 +21,9 @@
         - python-psycopg2
 
 - hosts: webservers
-  sudo: True
+  sudo: yes
   sudo_user: postgres
-  gather_facts: False
+  gather_facts: no
 
   vars:
     dbname: myapp