Remove metadata.json and update application readme.
Remove metadata.json and update application readme.

* Metadata.json can be generated with the rake tasks.
* Use 'metadata[cookbook]' and 'metadata_all' to generate .json.
* Application readme needed a few more clarification points.

gusrc/wordpress-cookbook,Nordstrom/wordpress,cookbooks/oc-wordpress,gusrc/wordpress-cookbook,petracvv/wordpress-cookbook,Design-Collective/wordpress-cookbook1,mconf-cookbooks/wordpress-cookbook,petracvv/wordpress-cookbook,mconf-cookbooks/wordpress-cookbook,veered/wordpress,brint/wordpress-cookbook,mconf-cookbooks/wordpress-cookbook,atomic-penguin/wordpress,atomic-penguin/wordpress,brint/wordpress-cookbook,petracvv/wordpress-cookbook,statlus/wordpress-cookbook,Design-Collective/wordpress-cookbook1,gusrc/wordpress-cookbook,gsreynolds/wordpress-cookbook,gsreynolds/wordpress-cookbook,statlus/wordpress-cookbook,gsreynolds/wordpress-cookbook,brint/wordpress-cookbook