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.

damiendurant/mysql,bluespurs/mysql,WeAreCloudar/mysql,manastech/mysql,krinkin/mariadb,martinb3-cookbooks/mysql,torchlight-dev/mysql,storozhilov/mariadb-enterprise,Amakata/mysql,mrb/mysql,juliandunn/mysql,martinb3-cookbooks/mysql,nkadel-skyhook/nkadel-mysql-cookbook,Amakata/mysql,edmunds-chef/mysql,cookbooks/mc-mysql,pyama86/mysql,shopping-adventure/chef_mysql,hmuronaka/mysql,chef-cookbooks/mysql,Krzana/mysql,krinkin/mariadb,juliandunn/mysql,neclimdul/chef-mariadb,GannettDigital/chef-mysql,hmuronaka/mysql,GannettDigital/chef-mysql,gh2k/mysql,PLOS/mysql,Krzana/mysql,edclements/chef-mysql,coletivoEITA/mysql-cookbook,Amakata/mysql,torchlight-dev/mysql,OSLL/mariadb-cookbooks,dwashko/chef-mysql,mrb/mysql,Pardot/mysql,ffuenf/mysql,ffuenf/mysql,coletivoEITA/mysql-cookbook,mattray/mysql,zuazo-forks/chef-cookbooks-mysql,broadinstitute/mysql,nkadel-skyhook/nkadel-mysql-cookbook,OSLL/mariadb-cookbooks,joseaomedes/mysql,cookbooks/oc-mysql,joerocklin/chef-mariadb,ffuenf/mysql,paulczar/cookbook-mariadb,gh2k/mysql,dwashko/chef-mysql,acoulton/mysql,gollub/mysql,bluespurs/mysql,mattray/mysql,neclimdul/chef-mariadb,geleman/mysql,broadinstitute/mysql,Krzana/mysql,rcbops-cookbooks/mysql,storozhilov/mariadb-enterprise,damiendurant/mysql,neclimdul/chef-mariadb,edmunds-chef/mysql,gh2k/mysql,bluespurs/mysql,OSLL/mariadb-cookbooks,gollub/mysql,mattray/mysql,geleman/mysql,krinkin/mariadb,umegaya/mysql,WeAreCloudar/mysql,cookbooks/hw-mysql,dwashko/chef-mysql,coletivoEITA/mysql-cookbook,torchlight-dev/mysql,PLOS/mysql,cookbooks/nd-chef-opscode-mysql,martinb3-cookbooks/mysql,joseaomedes/mysql,umegaya/mysql,geleman/mysql,umegaya/mysql,GannettDigital/chef-mysql,PLOS/mysql,shopping-adventure/chef_mysql,juliandunn/mysql,hmuronaka/mysql,acoulton/mysql,gollub/mysql,storozhilov/mariadb-enterprise,mrb/mysql,paulczar/cookbook-mariadb,damiendurant/mysql,acoulton/mysql,zuazo-forks/chef-cookbooks-mysql,joerocklin/chef-mariadb,chef-cookbooks/mysql,edmunds-chef/mysql,nkadel-skyhook/nkadel-mysql-cookbook,pyama86/mysql,pyama86/mysql,chef-cookbooks/mysql,WeAreCloudar/mysql,zuazo-forks/chef-cookbooks-mysql,manastech/mysql,joseaomedes/mysql