removed unused 'pattern' from ansible.cfg

also moved the config param to a 'deprecated' list in constants.py
added TODO for producing a deprecation warning for such vars

examples/ansible.cfg

@@ -14,7 +14,6 @@
 #inventory      = /etc/ansible/hosts
 #library        = /usr/share/my_modules/
 #remote_tmp     = $HOME/.ansible/tmp
-#pattern        = *
 #forks          = 5
 #poll_interval  = 15
 #sudo_user      = root